10th Physics
Important Multiple Choice Questions and answers
1. LIGHT: REFRACTION AND REFLECTION
1. An object is kept at the centre of curvature of a convex lens. The position and nature of the image formed is.
a) Between F and C and inverted.
b) Behind the mirror and erect.
c) Between F and P and erect.
d) At the centre of curvature and inverted.
Ans: d) at the centre of curvature and inverted.
2. When a beam of light travelling obliquely from one medium to another, the direction of propagation of light in the second medium changes this phenomenon is known as
a) Refraction of light. b) Reflection of light.
c) Dispersion of light. d) Total internal reflection of light.
Ans: a) Refraction of light.
3. Identify the correct option of first and second law of refraction of light.
i) Incident ray, refracted ray and normal to the interface of two transparent media at the point of incidence, all lie in same plane.
ii) Angle of incidence is equal to angle of reflection.
iii) Incident ray, normal to the mirror at point of incidence and reflected ray, all lies in the same plane.
iv) Ratio of sine of angle of incidence to Sine of angle of refraction is constant for light of given colour and pair of media.
a) i) and ii) b) ii) and iv)
c) i) and iv) d) iii) and iv)
Ans: c) i) and iv)
4. In which of the following media the light will it travel very fast compare to other media.[ diamond (RI = 2.42), kerosene (RI = 1.44), water (RI = 1.31), rock salt (RI = 1.54).]
a) Rock salt. b) Water c) Kerosene d) Diamond.
Ans: b) Water
5. In which of the following media is an optically denser and optically rarer.[ kerosene (RI = 1.44), water (RI = 1.31)]
a) Kerosene is a denser media and water is rarer medium.
b) Kerosene is a rarer media and water is denser medium.
c) Both the media's are rarer media.
d) Both the media's are denser media.
Ans: a) Kerosene is a denser media and water is rarer medium.
6. The ratio of sine of angle of incidence to the Sine of angle of refraction is a constant, for the light of a given colour and for the given pair of media This law is also known as.______.{This law is true for angle 0 < i < 90°}.
a) Law of reflection b) Snell’s law of refraction
c) ohm's law d) Dispersion.
Ans: b) snell's law of refraction
7. A lens may have two spherical surfaces, bulging outwards, such a lens is called.____
a) Concave lens. b) Plano concave lens.
c) Plano convex lens. d) Convex lens.
Ans: d) convex lens.
8. A lens may have two spherical surfaces, curved in words, such a lens is called.____
a) Concave lens b) convex lens.
c) Plano concave lens. d) Plano convex lens.
Ans: a) Concave lens
9. Which of the following is a converging lens?
a) Concave lens. b) Plano concave lens. c) Glass slab. d) Convex lens.
Ans: a) d) Convex lens.
10. Which of the following is a diverging lens?
a) Concave lens. b) Plano concave lens.
c) Glass slab. d)convex lens.
Ans: a) a) Concave lens.
11. The centre of the spherical refracting surface of the lens is called
a) Optic centre b) principal axis c) Pole. d) Centre of curvature.
Ans: c) Pole.
12. The point on the principal axis at the centre of the lens is called
a) Pole. b) Optical centre. c) Aperture. d) Focal point.
Ans: b) Optical centre.
13. A lens has two spherical surfaces; these two spherical surfaces form a part of a sphere. The centre of these spheres is known as
a) Focal point. b) Principal axis.
c) Pole. d) Centre of curvature.
Ans: d) Centre of curvature.
14. An imaginary line passing through the centres of curvature and the pole is called_____.
a) Principal axis. b) Centre of curvature.
c) Principal focus. d) Aperture.
Ans: a) Principal axis.
15. The area of the lens suitable for refraction is called
a) Principal axis. b) Centre of curvature
c) Aperture. d) Principal focus.
Ans: c) Aperture.
16. the point where a beam parallel to the principal axis appears to diverge or converges from a point on the principal axis after passing through the lens. Called_____
a) Optical centre b) Principal focus
c) Centre of curvature d) Principal axis
Ans: b) Principal focus
17. The distance between the optical centre and the focal point or focus of the lens called_____
a) Centre of curvature. b) Focal length.
c) Radius of curvature. d) Optical centre.
Ans: b) Focal length.
18. Ray of light from the object parallel to principal axis, after refraction from a convex lens passes through ______
a) Centre of curvature. b) Optical centre.
c) Principal focus. d) Beyond centre of curvature.
Ans: c) Principal focus.
19. A ray of light passing through or appearing to meet a principal focus, after refraction from the convex lens will emerge ______
a) Through optical centre. b) Through centre of curvature.
c) Through principal focus. d) Parallel to the principal axis.
Ans: d) Parallel to the principal axis.
20. A ray of light passing through the optical centre of a lens wills emerge_____
a) Through principal focus b) without any deviation.
c) Through centre of curvature. d) Parallel to the principal axis.
Ans: b) without any deviation.
21. In the experiment of refraction of light through a glass slab, which of the following situation refraction of light takes place When the,
a) Angle of incidence is 90°.
b) Angle of incidence is more than 90°.
c) Angle of incidence is less than 90°.
d) Angle of incidence is 0°.
Ans: c) Angle of incidence is less than 90°.
22. The image formed by convex lens is real, inverted and of the same size as that of the object. The position of object should be,
a) At the focus.
b) At the centre of curvature.
c) Between focus and centre of curvature.
d) Beyond centre of curvature.
Ans: b) At the centre of curvature.
23. Magnifying power of a concave lens is.
a) Always> 1 b) always < 1
c) always = 1 d) can have any value
Ans: b) always < 1
24. Magnifying power of a convex lens is.
a) Always> 1 b) always< 1 c) always = 1 d) can have any value
Ans: a) Always > 1
25. Which of the following is an correct Nature, Position of the image formed by convex lens when the object is placed at infinity.
a) Position of the image at 2F2 and Nature of the image is virtual and erect.
b) Position of the image at focus F2 and Nature of the image is real and inverted.
c) Position of the image at focus F2 and Nature of the image is virtual and erect.
d) Position of the image at infinity and Nature of the image is real and inverted.
Ans: b) Position of the image at focus F2 and Nature of the image is real and inverted.
26. Which of the following is a correct Position, and Relative size of the image formed by convex lens when the object is placed beyond centre of curvature (2F1).
a) Position of the image: between F2 and 2F2 and nature of image is real and inverted.
b) Position of the image: at infinity and nature of image is real and inverted.
c) Position of the image: beyond 2F2 and nature of image is virtual and erect.
d) Position of the image: at 2F2 and nature of image is virtual and erect.
Ans: a) Position of the image: between F2 and 2F2 and nature of image is real and inverted.
27. If the magnification produced by a lens has a negative value, the image will be.
a) Virtual and inverted b) virtual and erect
c) real and erect d) real and inverted
Ans: b) virtual and erect
28. If the magnification produced by a lens has a positive value, the image will be.
a) Virtual and inverted b) virtual and erect
c) real and erect d) real and inverted
Ans: d) real and inverted
29. The ratio of the height of the image and the height of the object is called_____
a) Power of lens. b) Magnification. c) De magnification. d) Snell’s law.
Ans: b) Magnification.
30. Choose the correct definition of power of lens.
a) Capacity to capture longer distance.
b) The reciprocal of its centre of curvature.
c) The reciprocal of its focal length.
d) Capacity to capture shorter distance.
Ans: c) The reciprocal of its focal length.
31. What is the meaning of 1 dioptre?
a) The power of a lens whose focal length is 1 metre.
b) The power of a lens whose focal length is 1 centimetre.
c) The power of a lens whose focal length is 1 millimetre.
d) The power of a lens whose focal length is 1 nanometre.
Ans: a) The power of a lens whose focal length is 1 metre.
32. By using following information identify the concave lens and convex lens. 'A' lens has power = - 0.25D 'B' lens has power = + 0.5D
a) 'A' lens is convex lens and 'B' lens is concave lens
b) 'A' lens is concave lens and 'B' lens is convex lens
c) We can't identify by using this given information.
d) 'A' and 'B' both are convex lens.
Ans: b) 'A' lens is concave lens and 'B' lens is convex lens
33. The focal length of convex lens is 0.25 m calculate the power of lens
a) +1D b) +2D c) +3D d) +4D
Ans: d) +4D
34. The laws of refraction hold good for
a) Plane mirror only b) concave mirror onl
c) convex mirror only d) concave lens.
Ans: d) concave lens.
35. The radius of curvature of a mirror is 20cm the focal length is
a). 20cm b). 10cm c). 40cm d). 5cm
Ans: a). 20cm
36. You are given three media A, B and C of refractive index 1.33, 1.65 and 1.46. The medium in which the light will travel fastest is
a) A b) B c) C d) equal in all three media.
Ans: a) A
37. The angle of incidence for a ray of light having zero reflection angle is
(a) 0 (b) 30° (c) 45° (d) 90°
Ans: a) 0
38. As light travels from a rarer to a denser medium it will have
(a) increased velocity (b) decreased velocity
(c) decreased wavelength (d) both (b) and (c)
Ans: (d) both (b) and (c)
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2. ELECTRICITY
1. What is the amount of current flowing through an electric press, if the amount of charge passing through a conductor in 10 minutes is 300 C?
A. 30 A B. 0.3 A C. 0.5 A D. 5 A
Answer: C. 0.5 A
2. In the given figure, the resistors
A. 6 Ω, 3 Ω and 9 Ω are in series
B. 9 Ω and 6 Ω are in parallel and the combination is in series with 3 Ω
C. 3 Ω, 6 Ω and 9 Ω are in parallel
D. 3 Ω and 6 Ω are in parallel and the combination is in series with 9 Ω
Answer: D. 3 Ω and 6 Ω are in parallel and the combination is in series with 9 Ω
3. When a current 'I' flows through a resistance 'R' for time’t’ the electrical energy spent is given by
A. IRt B. I2Rt C. IR2 t D. I2R/t
Answer: B. I2Rt
4. A wire of resistance R1 is cut into five equal pieces. These five pieces of wire are then connected in parallel. If the resultant resistance of this combination be R2, then the ratio R1/ R2 is:
A. 1/25 B. 1/5 C. 5 D. 25
Answer: D. 25
5. Which of the given is the SI Unit of Electric Current?
A. Ohm B. Ampere C. Volt D. Faraday
Answer: B. Ampere
6. A fuse wire is inserted in which wire?
A. Live wire B. In the neutral wire
C. In the earth wire D. May be connected in any line
Answer: A. Live wire
7. The rate of flow of an electric charge is known as:
A. Electric potential B. Electric conductance
C. Electric current D. None of these
Answer: C. Electric current
8. The instrument used for measuring electric current is:
A. Ammeter B. Galvanometer
C. Voltmeter D. Potentiometer
Answer: A. Ammeter
8. The relation between potential difference (V) and current (I) is :
A. V α I2 B. V α 1/I C. V2 α I D. V α I
Answer:D. V α I
9. Which of the given statements is not true, regarding the electrical set-up for the verification of Ohm’s law:
A. The voltmeter is connected in parallel with the known resistance
B. The ammeter is connected in series circuit
C. The rheostat can only increase the resistance in electric circuit
D. The single key is used to switch on/off the electric circuit
Answer:C. The rheostat can only increase the resistance in electric circuit
10. On which of the given resistance does not depend:
A. Length of conductor B. Area of cross-section
C. Temperature D. Density
Answer:D. Density
11. Which of the given statements is true regarding ammeter and voltmeter?
A. Ammeter is connected in series with the required device, Voltmeter in parallel
B. Both ammeter and voltmeter are connected in series with required device
C. The voltmeter is connected in series with the device, Ammeter in parallel
D. They can be connected in any way
Answer:A. Ammeter is connected in series with the required device, Voltmeter in parallel
12. An electric heater is rated at 2 Kw. Electrical energy costs Rs 4 per k Wh. What is the cost of using the heater for 3 hours?
A. Rs. 12 B. Rs. 24 C. Rs. 36 D. Rs. 48
Answer:B. Rs. 24
13. The commercial unit of energy is: A. Watt B. Watt-hour C. Kilowatt-hour D. Kilo-joule Answer:C. Kilowatt-hour 14. An electric fuse works on the:
A. Chemical effect of current
B. Magnetic effect of current
C. Lighting effect of current
D. Heating effect of current
Answer:D. Heating effect of current
15. A car headlight bulb working on a 12 V car battery draws a current of 0.5 A. The resistance of the light bulb is:
A. 0.5 Ω B. 6 Ω C. 12 Ω D. 24 Ω
Answer:D. 24 Ω
16. The resistivity of a certain material is 0.6 Ωm. The material is most likely to be:
A. An insulator B. A superconductor
C. A conductor D. A semiconductor
Answer:D. A semiconductor
17. If the amount of electric charge passing through a conductor in 10 minutes is 300 C, the current flowing is:
A. 30 A B. 12.03 A C. 12.05 A D. 5.00 A
Answer:C. 12.05 A
18. Keeping the potential difference constant, the resistance of a circuit is doubled. The current will become:
A. Double B. Half C. One-fourth D. Four times
Answer:B. Half
19. A battery of 10 volt carries 20,000 C of charge through a resistance of 20 Ω. The work done in 10 seconds is
(a) 2 × 103 joule (b) 2 × 105 joule
(c) 2 × 104 joule (d) 2 × 102 joule
Answer: b
Explanation: (b) W= qV= 20000 × 10 = 2,00, 000 = 2 × 105 J
20. A fuse wire repeatedly gets burnt when used with a good heater. It is advised to use a fuse wire of
(a) More length (b) less radius (c) less length (d) more radius
Answer: d
21. A cooler of 1500 W, 200 volt and a fan of 500 W, 200 volt are to be used from a household supply. The rating of fuse to be used is
(a) 2.5 A (b) 5.0 A (c) 7.5 A (d) 10 A
Answer: d
22. The resistivity does not change if
(a) The material is changed
(b) The temperature is changed
(c) The shape of the resistor is changed
(d) both material and temperature are changed
Answer: c
23. Coulomb is the SI unit of:
(a) Charge (b) current (c) potential difference (d) resistance
Answer: a
24. The heating element of an electric iron is made up of:
(a) Copper (b) nichrome (c) aluminium (d) iron
Answer: b
25. The electrical resistance of insulators is
(a) High (b) low (c) zero (d) infinitely high
Answer: d
26. Electric power is inversely proportional to
(a) Resistance (b) voltage (c) current (d) temperature
Answer: a
27. What is the commercial unit of electrical energy?
(a) Joules (b) Kilojoules (c) Kilowatt-hour (d) Watt-hour
Answer: c
28. Which of the following gases are filled in electric bulbs?
(a) Helium and Neon (b) Neon and Argon
(c) Argon and Hydrogen (d) Argon and Nitrogen
Answer: d
29. When electric current is passed, electrons move from:
(a) High potential to low potential.
(b) Low potential to high potential.
(c) In the direction of the current.
(d) Against the direction of the current.
Answer: b
30. Electrical resistivity of any given metallic wire depends upon
(a) Its thickness (b) its shape
(c) nature of the material (d) its length
Answer: c
31. An electric bulb is connected to a 220V generator. The current is 0.50 A. What is the power of the bulb?
(a) 440 W (b) 110 W (c) 55 W (d) 0.0023 W
Answer: b (Here, V = 220 V, I = 0.50 A, Power (P) = VI = 220 x 0.50 = 110 W)
32. 1 kWh = ……….. J
(a) 3.6 × 10-6 J (b) 1/3.6 × 106 J
(c) 3.6 × 106 J (d) 13.6 × 10-6 J
Answer: c
33. Two electric bulbs have resistances in the ratio 1:2. If they are joined in series, the energy consumed in them is in the ratio.
(a) 2:1 (b) 1:2 (c) 4:1 (d) 1:1
Answer: (b) 1:2
34. What is the rate of flow of electric charges called?
(a) Electric potential (b) Electric conductance
(c) Electric current (d) none of these
Ans. (c) Electric current
35. Which of the following is the SI Unit of Electric Current?
(a) ohm (b) ampere (c) volt (d) faraday
Ans: (b) ampere
36. Which instrument is used for measuring electric potential?
(a) Ammeter (b) galvanometer
(c) voltmeter (d) potentiometer
Ans: (c) voltmeter
37. When one unit electric charge moves from one point to another point in an electric circuit, then the amount of work done in joules is known as?
(a) Electric current (b) electric resistance
(c) Electric conductance (d) potential difference
Ans: (d) potential difference
38. The hindrance presented by material of conductor to the smooth passing of electric current is known as:
(a) Resistance (b) Conductance
(c) Inductance (d) None of these
Ans: (a) Resistance
39. The resistance of a conductor is directly proportional to:
(a) Its area of cross-section (b) density
c) melting point (d) length
Ans: (d) length
40. The purpose of a rheostat is:
(a) Increase the magnitude of current only
(b) Decrease the magnitude of current only
(c) Increase or decrease the magnitude of current
(d) none of these.
Ans: (c) Increase or decrease the magnitude of current
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3. MAGNETIC EFFECT OF ELECTRIC CURRENT
1. The magnetic field around a current carrying circular loop can be increased by
A. Increasing the radius of the coil.
B. Converting the coil into straight wire.
C. Decreasing the radius of the coil.
D. Reducing the amount of electric current through the coil.
Ans: C
2. Correct statement about the magnetic field produced by the solenoid is
A. There is a uniform magnetic field around the solenoid,
B. Magnetic field is same at all points inside the solenoid
C. Solenoid produces circular magnetic field around it.
D. Magnetic field varies at different points inside the solenoid.
Ans: B
3. Which of the given correctly describes the magnetic field near a long straight wire?
A. The field consists of straight lines perpendicular to the wire
B. The field consists of straight lines parallel to the wire
C. The field consists of radial lines originating from the wire
D. D.The field consists of concentric circles centred on the wire
Ans: D
4. The direction of magnetic lines of force around a straight wire current carrying conductor can be obtained by
A. Oersted’s experiment B. Right hand thumb rule
C. Flemings right hand rule D. Fleming left hand rule
Ans: B
5. The presence of magnetic field at a point can be detected by:
A. a Strong magnet B. a solenoid
C. a compass needle D. a current carrying wire
Ans: C
6. A positively charged particle (alpha particle) projected towards west is deflected towards north by a magnetic field. The direction of magnetic field is
A. towards south B. towards east
C. downward D. upward
Ans: D
7. An electron enters a magnetic field at right angles to it as shown in the figure. The direction of force acting on the electron will be
A. to the right B. to the left
C. out of the page D. into the page
Ans: C
8. Which of the following property of a proton doesn’t change while it moves freely in a magnetic field?
A. Mass B. speed C. velocity D. momentum
Ans: A
9. The direction of induced current can be obtained by:
A. Fleming’s left hand rule B. Right hand thumb rule
C. Fleming’s right hand rule D. Faraday experiment
Ans: C
10. Observe the diagram. The magnetic poles represented by P and Q respectively are
A. south (S) and south (S) B. north (N) and south (S)
C. north (N) and north (N) D. south (S) and north (N)
Ans: A
11. A domestic electric appliance requires alternating current of 15V. If 220V of alternating current is supplied to the house, then the device that helps in the functioning of that electric appliance is.
A. induction coil B. step up transformer
C. AC dynamo D. step down transformer
Ans: A
12. In Fleming’s right hand rule, middle figure indicates the direction of:
A. magnetic field B. induced electric current
C. mechanical energy D. motion of the conductor
Ans: B
13. The magnetic field inside a long straight solenoid-carrying current
A. is zero
B. decreases as we move towards its end
C. increases as we move towards its end
D. is the same at all points
Ans: D
4. Which of the following property of a proton can change while it moves freely in a magnetic field? (There may be more than one correct answer.)
A. mass B. Speed C. velocity D. Momentum
Ans: C&D
15. A positively-charged particle (alpha-particle) projected towards west is deflected towards north by a magnetic field. The direction of magnetic field is
A. towards south B. towards east
C. downward D. upward
Ans: D
16. A rectangular coil of copper wires is rotated in a magnetic field. The direction of the induced current changes once in each
A. two revolutions B. one revolution
C. half revolution D. one- fourth revolution
Ans: C
17. Which of the following correctly describes the magnetic field near a long straight wire?
A. The field consists of straight lines perpendicular to the wire
B. The field consists of straight lines parallel to the wire
C. The field consists of radial lines originating from the wire
D. The field consists of concentric circles centered on the wire
Ans: D
18. The phenomenon of electromagnetic induction is
A. the process of charging a body
B. the process of generating magnetic field due to a current passing through a coil
C. producing induced current in a coil due to relative motion between a magnet and the coil
D. the process of rotating a coil of an electric motor
Ans: C
19. The device used for producing electric current is called a
A. generator B. galvanometer C. ammeter D. Motor
Ans: D
20. The essential difference between an AC generator and a DC generator is that
A. AC generator has an electromagnet while a DC generator has permanent magnet.
B. DC generator will generate a higher voltage.
C. AC generator will generate a higher voltage.
D. AC generator has slip rings while the DC generator has a commutator.
Ans: D
21. At the time of short circuit, the current in the circuit
A. reduces substantially
B. does not change
C. increases heavily
D. vary continuously
Ans: C
22. The magnetic field lines outside a bar magnet:
A. Originate from the South pole and end at its North Pole
B. Originate from the North pole and end at its East Pole
C. Originate from the North Pole and end at its South Pole
D. Originate from the South pole and end at its West Pole
Ans: C
23. The north pole of Earth’s magnet is in the:
A. Geographical South B. Geographical East
C. Geographical West D. Geographical North
Ans: A
24. A soft iron bar is inserted inside a current-carrying solenoid. The magnetic field inside the solenoid:
A. Will decrease B. Will increase
C. Will become zero D. Will remain the same
Ans: B
25. A current carrying conductor is held in exactly vertical direction. In order to produce a clockwise magnetic field around the conductor, the current should be passed in the conductor:
A. From top to bottom B. From left to right
C. From bottom to top D. From right to left
Ans: A
26. The force exerted on a current carrying wire placed in a magnetic field is zero when the angle between wire and the direction of magnetic field is:
A. 45o B. 60o C.90o D.180o
Ans: D
27. An induced emf is produced when a magnet is moved into a coil. The magnitude of induced emf doesnot depend on:
A. The speed with which the magnet is moved
B. The number of turns of the coil
C. The resistivity of the wire of the coil
D. The strength of the magnet
Ans: C
28. A positive charge is moving towards a person. The direction of magnetic field lines will be in clockwise direction
A. Anticlockwise direction
B. Vertically upward direction
C. Vertically downward direction
D. Clockwise direction
Ans: A
29. A fuse should always be placed in the
A. Live wire of the main circuit
B. Neutral wire of the main circuit
C. Earth wire of the main circuit
D. Bothe live and neutral wire of the main circuit.
Ans: A
30. The shape of the magnetic field lines produced by a current carrying conductor is:
A. Straight lines B. Concentric circles
C. Concentric ellipse D. Concentric parabolas
Ans: B
31. An electric motor is a device which transforms
A. Mechanical energy into electrical energy
B. Electrical energy into mechanical energy
C. Kinetic energy into potential energy
D. Electrical energy into Potential energy
Ans: B
32. in Right hand thumb rule, thumb indicates the direction of------
A. Current B. Motion of conductor
C. Magnetic force D. Mechanical force
Ans: B
33. How can you increase the strength of magnetic field around a current carrying conductor?
A. By increasing the strength of current through the conductor.
B. By decreasing the length of the conductor
C. By decreasing the strength of current through the conductor.
D. By using conductor of high resistance.
Ans: A
34. As we move away from a current carrying conductor the strength of magnetic field
A. decreases B. increases
C. remains the same D. depends on length of the conductor
Ans: A
35. Around a current carrying conductor magnetic field lines are arranged like
A. Straight lines parallel to conductor
B. Straight lines perpendicular to conductor.
C. Concentric circles perpendicular to the plane of conductor
D. Concentric circles in the plane of conductor.
Ans: C
36. Referring the figure given below, which of the following is correct regarding magnetic field at various points?
A. A=C=D >B B. A>B>C>D
C. A=C < D < B D. A = C > D > B
Ans: D
37. Hold a current-carrying straight conductor in your right hand such that the …….. Points towards the direction of current. Then fingers which circle around the conductor indicate the direction of the field lines.
A. fore finger B. middle finger C. thumb D. little finger
Ans: C
38. Select the correct use of solenoid.
A. To produce uniform magnetic field.
B. To magnetize a piece of magnetic material.
C. to change the direction motion of a beam of electrons
D. All the above.
Ans: D
39. A current through a horizontal power line flows in east to west direction. What is the direction of magnetic field at a point directly below it?
A. Towards north B. towards south
C. Towards east D. towards west
Ans: B
40. The rule which gives the direction of magnetic field around a current carrying Conductor is
A. Left hand thumb rule B. Right Hand Thumb Rule
C. Fleming’s Left hand rule D. Fleming’s Right hand rule
Ans: B
41. Which are the following are Commutators
A. Split rings B. Brushes C. Axel D. Magnets
Ans: A
42. The direction of current changes in every
A. 1 revolution B. 2 revolution
C. Half revolution D. 4 revolution
Ans: C
43. In left hand thumb rule direction of current is indicated by
A. Fore finger B. Middle finger
C. Thumb D. None of the above
Ans: B
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4. SOURCES OF ENERGY
1) Energy equivalent of one a.m.u is
a)2.29MeV b)15MeV c)931MeV d)96MeV
Ans: c. 931MeV
2) A quarter of our energy requirement in India is met by
a) Hydro power plant b) Thermal power plant
c) Geothermal power plant d) none of the above
Ans: a) Hydro power plant
3). Correct sequence of energy conversion in wind mill is
a)mechanical energy--->wind energy-->electric energy
b) Wind energy-->mechanical energy-->electric energy
c) Mechanical energy-->electric energy-->wind energy
d)electric energy-->wind energy-->mechanical energy
Ans: b) wind energy-->mechanical energy-->electric energy
4) Ocean thermal energy is due to
a) Number of minerals is more
b) Tides arising out in the Ocean
c)Temperature difference at different levels in the ocean
d)Pressure difference at different levels in the ocean
ans: c)Temperature difference at different levels in the ocean
5) which country is famous as "Country of winds"
a) India b) Denmark c) Newzealand d ) West indies
Ans: b) Denmark
6) Find false statement about Biogas
a) It contains up to 75% of methane
b) It burns without smoke
c) Leaves residue like ash in wood &charcoal
d) Heating capacity is high
Ans: c) Leaves residue like ash in wood and charcoal
7) If we increase the height of the water reservoir, what will happen?
a) Hindrance in water movement
b) More electricity produces
c) Less electricity produces
d) Damage in turbine
Ans:b) more electricity produces.
8). Choose the incorrect statement about renewable energy sources
a) They are pollution free
b) They are abundant
c) They are also called as inexhaustible
d) Petrol is also renewable source of energy
Ans: d) petrol is also renewable source of energy
9). the process by which energy is produced in the sun is
a) Nuclear fusion b) Nuclear fission
c) both a & b d) combustion of hydrogen
Ans: a) nuclear fusion
10) Quality of fuel is measured by
a) initial value b) combustion value
c) Calorific value d) none of the above
Ans: c) Calorific value
11) Full form of OTEC
a) Ocean thermal energy conversion
b) Ocean thermal energy combination
c) Ocean technical energy conversion
d) Ocean technical energy combination
Ans: a) Ocean thermal energy conversion plant
12) Minimum speed of wind to run a windmill
a) 5km) h b) 15km/h c) 25km/h d) 35km/h
Ans: a) 15km/h
13) Wind energy is used to
i) Produce electricity
ii) Draw underground water
iii) Operate water pumps Among these which is/are correct.
a)I&ii b)i&iii c)ii d)i,ii,iii
Ans:d)i,ii,iii
14) Ultimate source of energy is
a) Water b) air c) forest d )sun
Ans: d) sun
15) Bio-gas is produced from bio- mass by
a) Destructive distillation b) Fractional distillation
c) Evaporation d) anaerobic fermentation
Ans: d) anaerobic fermentation
16). If we lit a candle, there is heat and light. It is
a) Exothermic b) Endothermic
c) galvanization d) none of the above
Ans : a) Exothermic
17) Spent slurry is rich in
a ) Nitrogen and phosphorus
b) Oxygen and Carbon dioxide
c) Magnesium and carbon dioxide
d) Oxygen and magnesium
Ans: a) Nitrogen and phosphorus
18) There are 4 fuels which all contain only carbon and hydrogen, the fuel having highest calorific value will be one which has:
a)less of carbon as well as less of hydrogen
b) more of carbon but less of hydrogen
c)equal proportions of carbon & hydrogen
d) less of carbon but more of hydrogen
Ans: d) less of carbon but more of hydrogen
19) The power generated in a wind mill
a) Is more in winter season
b) is more in rainy season
c) Depends on the height of the tower
d) depends on wind velocity
Ans: d) depends on wind velocity
20) the most used nuclear fuel in the world is
a) plutonium-239 b) Uranium-235
C) Uranium-238 d) Thorium-232
Ans: b) Uranium- 235
21) What will generate when underground water comes in contact with the hot spot
a) Steam b) Ore c) Mercury d) None of the above
Ans: a ) Steam
22) Expanded form of CNG is
a) Compressed Natural gas
b) Common natural gas
c) Compressed national gas
d) Controlled natural gas
Ans:- a) Compressed Natural Gas
23) Wind intensity can be described by
a) Avogadro number b) Reynolds number
c) Mach number d) Beaufort number
Ans: d) Beaufort number
24) Hydro power plants are located
a) Plane area b) Desert
c) Hilly area d) none of the above
Ans: c) Hilly area
25) The optimum value of pH inside the digester for the biodegradation process
a) 2-3 b) 4.6- 4.8 c) 6.5 to 8 d) 9-10
Ans:- c) 6.5 to 8
26) Which of the following is not an example of bio- mass energy source?
a) coal b ) gobar gas c) wood d) nuclear energy
Ans: d) nuclear energy
27) This is not an example for renewable energy
a) Solar energy b) wind energy
c) Ocean energy d) natural gas
Ans: d) natural gas
28) The minimum temperature difference required between surface water at depth of upto 2km in an ocean thermal energy plant
a) 10°C b) 20°C c) 30°C d) 40°C
Ans:- b) 20°C
29) Tidal power plant consists of:
a) Power house b) dam or barrage
c) Sluice ways and gates d)all the above
Ans: d) all the above
30) The blades in wind turbines are connected to
a) string b) tower c) foundation d) nacelle
Ans- d) nacelle
31) What type of energy derived from heated ground water
a) Geothermal energy b) tidal energy
c) wind energy d) solar energy
Ans: a) geothermal energy
32) Good Source of energy should be
a)easily accessible b)easy to store and transport
c) be economical d)all the above
Ans: d) all the above
33)The largest Component of bio- gas is
a)butane b)methane c)Carbon di oxide d)Nitrogen
Ans: b) methane
34) Statement: charcoal is considered to be a better fuel than wood Reasons:
i) charcoal has higher calorific value
Ii) charcoal is comparatively smoke less
iii)charcoal burns without flame Which reason/s justify the statement
a) i b) ii c) ii & iii d) I,ii,iii
Ans: d) I,ii,iii
35) In a Hydro power plant:
a) Water is converted into steam to produce electricity
b) Electricity is extracted from water
c) Kinetic energy possessed by stored water is converted into potential energy
d) Potential energy possessed by stored water is converted into electricity
Ans: d) Potential energy possessed by stored water is converted into electricity
36) The disposal of wastes produced in a nuclear power plant is a big problem. Because
a) Highly inflammable b) highly reactive
c) Bad smell d) too light
Ans: b) highly radioactive
37) Constructing dams over rivers. It helps
a) to generate hydro electricity b)to irrigate agriculture land
c) to control floods over river d) all the above
Ans: d) all the above
38) Which of the following is more environment friendly
a)burning of kerosene b) burning of coal
c) Burning if charcoal d) burning of petrol
Ans: c) burning of charcoal
39) The inner wall of the solar cooker is painted black because
a) Prevents from rusting b) reflects light
c) Absorbs more heat d) none of the above
Ans: c) absorbs more heat
40) Gas which is present in both bio-gas and natural gas
a) methane b) sulphur dioxide
c) Oxygen d) carbon monoxide
Ans: a) methane
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