Important MCQ - Class 10 Science

      PHYSICS       

  Electricity  

1. The S I unit of potential difference is 

 (A) volt (V) 

 (B) ampere (A) 

 (C) coulomb (C) 

 (D) ohm meter (Ωm) 

Ans: (A) volt (V) 

2. The S I unit of electric current is 

 (A) ampere (A) 

 (B) ohm (Ω) 

 (C) volt (V) 

 (D) watt (W) 

Ans: (A) ampere (A) 

3. The rate of energy consumed in an electrical circuit is, electric  

 (A) current 

 (B) potential difference 

 (C) resistance 

 (D) power 

Ans: (D) power

4. When three resistors of different resistance are connected in parallel in an electric circuit and switched on, then the quantity that remains the same in all the resistors is 

 (A) current 

 (B) potential difference 

 (C) resistance 

 (D) resistivity 

Ans: (B) potential difference 

5. The SI unit of resistivity is 

 (A) ohm-metre 

 (B) coulomb 

 (C) volt 

 (D) joule 

Ans: (A) ohm-metre

6. The correct formula that shows the relationship between potential difference, electric current and resistance in an electric circuit is 

(A) I = R/V 

 (B) I=VR 

 (C) V=I/R

 (D) R=V/I

Ans: (D) R=V/I

7. A piece of metallic wire of resistance R is cut into 3 equal parts. These parts are then connected in parallel. If the total resistance of this combination is Rl, then the value of R : Rl is 

 (A) 1 : 3 

 (B) 9 : 1      

 (C) 1 : 9 

 (D) 3 : 1.

Ans: (B) 9 : 1

8. The resistance of a conductor is 27 Ω . If it is cut into three equal parts and connected in parallel, then its total resistance is 

 (A) 6 Ω 

 (B) 3 Ω

 (C) 9 Ω 

 (D)27 Ω

Ans: (B) 3 Ω

9. SI unit of electric charge is 

 (A) coulomb 

 (B) ampere

 (C) joule 

 (D) volt

Ans. : (A) coulomb   

10. In an electric circuit to get an equivalent resistance Rs four resistors of 2Ω each are first connected in series. Later to get an equivalent resistance of Rp the same resistors are connected in parallel. Then the ratio of Rs/Rp is

 (A) 16 : 1 

 (B) 2 : 1 

 (C) 4 : 1 

 (D) 8 : 1

Ans. : (A) 16 : 1 

11. Ohm's law gives the relationship between 

(A) potential difference and electric charge 

(B) potential difference and resistance

(C) electric current and potential difference

(D) electric current and electric power 

Ans: (C) electric current and potential difference

12. 0·75A current flows through an electric bulb when it is connected to a 220 V generator. Then the electric power of this bulb is 

 (A) 125 W 

 (B) 135 W 

 (C) 165 W 

 (D) 195 W 

Ans. : (C) 165 W 

13. If a device of 840W is to be used with 220V potential difference, then the rate of the fuse that is to be connected in this electrical circuit is 

 (A) 2A 

 (B) 4A 

 (C) 8A 

 (D) 12A 

Ans. : (B) 4A

  Magnetic effects of electric current  

 1. Observe the figure given below. The magnetic field at the centre ‘C’ of circular coil is 

(A) zero 

(B) I 

(C) 2I1 

(D) 2I2

Ans: (A) zero

2. Correct statement with respect to magnetic field in the given diagram is,

(C → Current-carrying solenoid, P and Q → Points inside the solenoid,R→ Point outside the solenoid) The magnetic field

(A) in P is more than in Q

(B) in Q is more than in P

(C) in R is more than in P and in O

(D) in P and in Q is equal.

Ans: (D) in P and in Q is equal.

3. Observe the diagram.

The magnetic poles represented by P and Q respectively are  

(A) south ( ) and south (S)

(B) north ( N ) and south ( S )

(C) north (N) and north (N)

(D) south (S) and north (N)

Ans. :  (A) south (S) and south (S) 

4. Imagine, you are holding a straight current carrying conductor as per the right hand thumb rule. If the thumb is upward, then the direction of the field lines of the magnetic field is 

(A) downward          

(B) upward

(C) anti-clockwise  

(D) clockwise.

Ans. : (C) anti-clockwise

5. In Fleming’s left hand rule the middle finger represents the direction of 

(A) magnetic fieldb                  

(B) current 

(C) movement of conductor  

(D) induced current 

Ans. : (B) current 

6. The magnetic field inside a long straight solenoid carrying current 

(A) is the same at all points 

(B) is zero 

(C) decreases as we move towards its end 

(D) increases as we move towards its end 

Ans. : (A) is the same at all points

7. A current carrying rod is placed between the poles of a horse-shoe magnet. For the maximum displacement of the rod the angle between the direction of electric current and the direction of magnetic field must be 

(A) 0°        

(C) 90°       

(B) 45°        

(D) 180° 

Ans. : (C) 90°

8. In Fleming’s left hand rule, the finger that indicates the direction of the electric current is (

 (A) thumb 

(B) index finger 

(C) middle finger 

(D) little finger 

Ans. : (C) middle finger 

9. If the number of turns in a current carrying circular coil is increased by 10 times, then the producing magnetic field increases by 

 (A) 100 times    

(B) 10 times

(C) 20 times      

(D) 1000 times 

Ans. : (B) 10 times

  LIGHT – REFLECTION AND REFRACTION  

1. The reciprocal of focal length of lens is 

(A) the power of lens

(B) the radius of curvature of lens

(C) equal to the sum of object distance and image distance

(D) equal to the difference between the object distance and image distance

Ans: (A) the power of lens

2. A mirror produces erect and enlarged image of an object. Then the type of mirror and the nature of that image is respectively 

(A) Convex mirror and virtual image

(B) concave mirror and real image

(C) Convex mirror and real image

(D) Concave mirror and virtual image

Ans: (D) Concave mirror and virtual image

3. The diameter of the reflecting surface of a spherical mirror is 

(A) pole of the mirror 

(B) centre of curvature 

(C) principal axis 

(D) aperture

Ans: (D) aperture

4. The distance between principal focus and the optic centre of the lens is 

(A) Radius of curvature 

(B) Object distance 

(C) Focal length 

(D) Image distance

Ans: (C) Focal length

5. The correct statement among the following related to the concave lens is 

(A) converges the light rays

(B) diverges the light rays

(C) forms inverted image

(D) forms real image.

Ans. : (B) diverges the light rays

6. To get diminished and real image of an object from a convex lens, the object should be placed 

(A) at principal focus F1

(B) between principal focus F1 and 2F1

(C) beyond 2F1

(D) between principal focus F1 and optical centre O.

Ans. : (C) beyond 2F1

7. An object is kept at the centre of curvature of a concave mirror. 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. 

8. To obtain a diminished image of an object from a concave mirror, position of the object should be (F = principal focus, C = centre of curvature, P = pole) (April 2019)

(A) between C and F

(B) beyond C

(C) between P and F

(D) at F 

Ans. : (B) beyond C

9. Identify the emergent ray in the given figure. 

 A) CD 

 (B) BC 

 (C) AB 

 (D) IJ

Ans. : (A) CD  

10. Type of the mirror used in vehicles as rear view mirror is 

 (A) plane mirror 

(B) concave mirror

(C) convex mirror

(D) planoconcave mirror

Ans. : (C) convex mirror.

11. To get virtual and erect image by a convex lens, an object is to be placed 

(A) beyond 2F1

(B) between F1 and 2F1 ]

(C) at focus F1 

(D) between focus F1 and optical centre O 

Ans. : (D) between focus F1 and optical centre O.  

12. Convex mirrors are used in 

 (A) torches 

 (B) rear view mirrors in vehicles 

(C) search-lights 

 (D) shaving mirrors  

Ans. : (B) rear view mirrors of vehicles

  Human Eye and Colorful World       

1. The sky as seen from the surface of the moon appears dark because

(A) only a little of the blue and violet colours are scattered

(B) all the colours are absorbed by the atmosphere present in the moon

(C) all the colours are scattered Total

(D) atmospheric particles needed to scatter the light are not present.

Ans. : (D) atmospheric particles needed to scatter the light are not present.

2. Right statement regarding the colour of the scattered sunlight and the size of scattering atmospheric particles is 

(A) small particles scatter red colour 

(B) big particles scatter blue colour 

(C) big particles scatter violet colour 

(D) too larger particles scatter all colours equally 

Ans. : (D) too larger particles scatter all colours equally 

3. The colour that is least scattered by fog and smoke is 

 (A) orange 

 (B) blue 

 (C) red 

 (D) violet 

Ans. : (C) red 

4. Identify the wrong statement among the following statements regarding refraction and dispersion of light. 

(A) Stars twinkle 

(B) Sky appears blue to an astronaut flying at very high altitudes 

(C) The sun is visible to us about two minutes before the actual sunrise 

(D) Planets do not twinkle 

Ans. : (B) Sky appears blue to an astronaut flying at very high altitudes

5. The crystalline lens of the eye in old age people sometimes becomes milky and cloudy. This condition is called 

(A) Hypermetropia 

(B) Myopia            

(C) Presbyopia 

(D) Cataract

Ans: (D) Cataract

6. The sun is visible to us about two minutes before the actual sunrise and about two minutes even after the actual sunset because of atmospheric 

(A) refraction of light Total 

(B) reflection of light 

(C) scattering of light 

(D) dispersion of light 

Ans. : (A) refraction of light

7. Observe the diagrams given below : 

The correct conclusion that you can draw here is that, the angle of deviation will be 

(A) maximum in Q 

 (B) minimum in P 

(C) more in P than in Q 

(D) more in R than in Q

 Ans. : (A) maximum in Q

     CHEMISTRY     

  Chemical Reactions and Equations  

1. Silver chloride turns grey when exposed to sunlight. This is because silver chloride 

(A) decomposes to form silver. 

(C) combines with oxygen. 

(B) decomposes to form chlorine. 

(D) reacts with atmospheric moisture.

Ans: (A) decomposes to form silver. 

2. The type of chemical reaction in which reactants exchange their ions is 

 

(A) Double displacement 

 

(B) Displacement

 

(C) Decomposition 

 

(D) Combination 

Ans: (A) Double displacement 

3.

Analyse the experiment expressed in the above figure. The molecular formulae of the solution ‘Y’ that gives a yellow colour precipitate by reacting with KI solution and the another product that forms here respectively are. 

(A) Pb(NO3)2 and KNO3 

(B) PbI2 and KNO3 

(C) Pb(NO3)2 and KI 

(D) Pb(NO3)2 and K2SO4   

Ans: (B) PbI2 and KNO3

4. The metal that displaces copper from copper sulphate solution is 

 (A) mercury 

 (B) gold 

 (C) iron

 (D) silver 

Ans. : (C) iron

 

5. The gas liberated at the cathode in the electrolysis of water is

(A) Oxygen 

(B) Hydrogen      

(C) Chlorine 

(D) Nitrogen.  

Ans. : (B) Hydrogen

6. Fe2O3 + 2 Al → Al2O3 + 2 Fe The type of above chemical reaction is (June 2019)

A) combination reaction     

(B) double displacement reaction

(C) decomposition reaction   

(D) displacement reaction

Ans: (D) displacement reaction

7. The reactants that exchange ions by reacting with each other and form a precipitate among the following are

(A) BaCl2 and Na2SO4

(B) Al2O 3 and HCl

(C) NaOH and H2SO4

(D) Na2O and CO2

Ans. : (A) BaCl2 and Na2SO4

8. Chips manufacturers, flush bags of chips with nitrogen gas because, to

(A) prevent corrosion of chips

(B) prevent chips from getting oxidised

(C) make chips undergo rancidity

(D) prevent the chips from getting reduced.

Ans. : (B) prevent chips from getting oxidised

9. A type of chemical reaction in which a single product is formed by two or more reactants is  

(A) chemical decomposition        

(B) chemical combination

(C) chemical displacement           

(D) chemical double displacement 

Ans:  (B) chemical combination

10. Ferrous sulphate crystals lose green colour when heated. Because this compound 

(A) decomposes into simpler products

(B) loses water molecules

(C) releases sulphur dioxide gas

(D) produces brown fumes

Ans. : (B) loses water molecule

11. In the electrolysis of water the gases that are released at cathode and anode and their ratio respectively are, 

(A) Hydrogen:Oxygen ; 1:2               

(B) Oxygen:Hydrogen ; 2:1

(C) Hydrogen : Oxygen : 2:1               

(D) Oxygen : Hydrogen ; 1:2

Ans. : (C) Hydrogen : Oxygen ; 2:1

12. The electrolysis of water to form hydrogen and oxygen gases is 

 (A) an endothermic reaction 

(B) a displacement reaction 

(C) an exothermic reaction 

(D) a redox reaction 

Ans: (A) an endothermic reaction 

13. The reactants that exchange ions by reacting each other and form a precipitate among the following are 

(A) Aluminium oxide and hydrochloric acid 

(B) Sodium hydroxide and sulphuric acid 

(C) Aluminium oxide and hydrochloric acid 

(D) Barium chloride and sodium sulphate 

Ans: (D) Barium chloride and sodium sulphate 

14. ZnO + C → Zn + CO ; the reactants that are oxidised and reduced in this chemical reaction respectively are 

(A) ZnO and C 

(B) C and ZnO 

(C) Zn and CO 

(D) Co and Zn 

Ans: (B) C and ZnO

15. 2AgCl → 2Ag+ Cl; the type of this chemical reaction is 

(A) Combination reaction 

(C) Decomposition reaction 

(B) Displacement reaction 

(D) Double displacement reaction 

Ans: (C) Decomposition reaction 

16. The gas flushed to the bags containing chips is 

(A) Hydrogen  

(B) Oxygen 

(C) Chlorine 

(D) Nitrogen 

Ans. : (D) Nitrogen

17. 

In this chemical reaction, 

(A) hydrogen is reduced to form water

(B) exchange of ions took place between the reactants

(C) copper oxide is oxidised to form copper

(D) copper oxide is reduced to form copper

Ans. : (D) copper oxide is reduced to form copper

18. Zn + CuSO4 → ZnSO4 + Cu

The above reaction is an example for 

(A) Endothermic reaction

(B) Precipitation reaction

(C) Displacement reaction

(D) Double displacement reaction

Ans. :  (C) Displacement reaction

    Acids, Bases and Salts   

1. The chemical formula of bleaching powder is

(A) NaCl 

(B) Na2CO3 

(C) CaCO3 

(D) CaOCl2

Ans: (D) CaOCl2

2. As the pH value of a neutral solution increase, 

(A) basic property decreases and number of OH− ions increases.

(B) acidic property increases and number of H+ ions decreases.

(C) basic property increases and number of OH− ions increases.

(D) acidic property decreases and number of H+ ions increases.

Ans: (C) basic property increases and number of OH− ions increases.

3. When CO2 gas is passed through a clear solution of X, this solution milky. When CO2 supply is continued, this milky solution turns clear solution due to the formation of salt Y. In this reaction X and Y is. 

(A) Calcium carbonate and calcium hydroxide

(B) Calcium hydrogen carbonate and calcium chloride

(C) Calcium hydroxide and calcium hydrogen carbonate

(D) Calcium carbonate and calcium hydrogen carbonate

Ans: (C) Calcium hydroxide and calcium hydrogen carbonate

4. The chemical equation that represents neutralization reaction among the following is  

Ans: C

5. As the pH value of a solution increases. 

A) number of H+ ions increases

B) number of OH– ions increases

C) number of OH– ions decreases

D) equal number of H+ and OH– ions

Ans: B) number of OH– ions increases

6. The gas liberated when an acid reacts with a metal is: 

A. Hydrogen                  

B. Chlorine

C. Carbon dioxide        

D. Nitrogen dioxide

Ans: A. Hydrogen

7. The substance that converts red litmus paper into blue colour is 

(A) KOH Solution

(B) distilled water

(C) dilute solution of HCl

(D) concentrated solution of HNO3

 

Ans : (A) KOH Solution

8. The pH value of a solution that turns blue litmus paper into red colour is 

(A) 5        

(B) 7    

(C) 9       

(D) 14

Ans. :   (A) 5

9. A salt used to remove the permanent hardness of water is

(A) calcium sulphate hemihydrate 

(B) calcium oxychloride 

(C) sodium carbonate

(D) sodium hydrogen carbonate

Ans: (C) sodium carbonate

10. When excess of sodium hydroxide is dissolved in the same basic solution then

(A) the concentration of OH − ions increases 

(B) the concentration of H3O+ ions increases

(C) the pH value of the solution decreases 

(D) the concentration of OH − ions decreases.

Ans: (A) the concentration of OH − ions increases 

   Metals and Non Metals  

1. The constituent metals in brass are 

(A) copper and zinc 

(B) aluminium and tin 

(C) copper and tin 

(D) zinc and aluminium

Ans: (A) copper and zinc 

2. To make iron to be hard and strong 

(A) carbon is added to pure iron 

(B) zinc is added to pure iron

(C) fused with some other metals 

(D) anodization will be done

Ans: (A) carbon is added to pure iron

3. CuSO4 + Fe → FeSO4 + Cu

2AgNO3 + Cu → Cu(NO3)2 +2Ag

(A) Copper is more reactive than iron and silver

(B) Iron is less reactive than copper and silver

(C) Copper is more reactive than silver but less reactive than iron

(D) Silver is more reactive than copper and iron.

Ans: (C) Copper is more reactive than silver but less reactive than iron

4. To make pure iron hard and strong, the substance that is to be added to it is

 

(A) carbon 

(B) zinc 

(C) nickel 

(D) tin

Ans: (A) carbon

5. A + Salt solution of B → Salt solution of A + B. A and B in this word equation are metals. These metals respectively are 

(A) copper and sodium 

(B) lead and aluminium

(C) Hydrogen with oxygen 

(D) magnesium and zinc

Ans: (D) magnesium and zinc

6. The possible chemical reaction among the following is 

Ans:  C

7. The electronic configuration of element X is 2, 8, 8, 1 and the electronic configuration of element Y is 2, 8, 7. Then the type of bond formed between these two elements is 

(A) covalent bond   

(B) hydrogen bond

(C) metallic bond    

(D) ionic bond

Ans: (D) ionic bond

8. The amphoteric oxide among the following is 

A) Potassium oxide   

B) Sodium oxide 

C) Calcium oxide        

D) Zinc oxide

Ans: D) Zinc oxide

9. Which of the following will give displacement reactions? 

 A) NaCl solution and Copper metal.

B) MgCl2 solution and Aluminium metal.     

C) FeSO4 solution and Silver metal.

D) AgNO3 solution and Copper metal.

Ans: D) AgNO3 solution and Copper metal.

10. Silver articles become black on prolonged exposure to air; this is due to the formation of

a) silver sulphide

b) silver nitride

c)silver carbonate

d) silver oxide

Ans: a) silver sulphide

11. Aluminium, Iron, Magnesium and Zinc metals react with dilute hydrochloric acid. The series that indicates decreasing order of reactivity of these metals is 

(A) Mg > Al > Zn > Fe 

(B) Al > Mg > Fe > Zn 

(C) Fe > Zn > Al > Mg 

(D) Fe > Mg > Zn > Al

Ans. :  (A) Mg > Al > Zn > Fe 

12. The electronic configuration of the three elements P, Q and R respectively are 2, 8, 2 ; 2, 8 and 2, 8, 7. Among these, the elements that can react with each other to produce an ionic compound are 

(A) P and Q        

(B) P and R 

 (C) Q and R       

(D) P, Q and R 

Ans. : (B) P and R 

13. The metal that exists in liquid state at room temperature is (July 2023)

 (A) Mercury          (B) Silver 

(C) Sodium            (D) Gold 

Ans. : (A) Mercury 

14. An alloy that is made up of copper and zinc is

 (A) solder metal   

(B) bronze 

 (C) brass               

(D) stainless steel

Ans: (C) brass

15. The gas liberated when sodium bicarbonate reacts with dilute hydrochloric acid is

(A) Carbon dioxide 

(B) Nitrogen 

(C) Hydrogen 

(D) Nitrogen dioxide

Ans: (A) Carbon dioxide 

16. Electronic configurations of the elements A, B and C respectively are 2, 8, 2 ; 2, 8 and 2, 8, 7. Among these the elements that can react each other to form an ionic compound are

(A) Elements A and B 

(B) Elements B and C 

(C) Elements A and C 

(D) Elements A, B and C

Ans: (C) Elements A and C

  CARBON AND IT'S COMPOUNDS   

1. A property of carbon that is responsible for giving rise large molecules is 

(A) tetravalency 

(B) catenation 

(C) inflammability 

(D) allotropism

Ans: (B) catenation 

2. The functional group present in pentanal is

(A) - OH 

(B) - CHO 

(C) - COOH 

(D) - CO -

Ans: (B) - CHO 

3. Another structure with the same molecular formula of the compound in the following structural Formulas 

Ans: (D)

4. The ′𝒙′ in the following reaction represents, 

(A) K2Cr2O7 

(B) KMnO4 

(C) NaOH 

(D) KOH

Ans: (B) KMnO4 

5. Number of single bonds found in the molecular structure of propanal is 

 (A) 8      

(C) 7    

(B) 6    

(D) 5

Ans. : (A) 8

6. Identify the correct electron dot structure of nitrogen molecule in the following 

7. The name and the molecular formula of the unsaturated hydrocarbon having general formula CnHn2 and containing 3 carbon atoms is 

(A) propane, C3H8

(B) Cyclopropane, C3H6

(C) Propyne, C3H4   

(D) Propene, C3H6

Ans. : (D) Propene, C3H6.

8. An example for saturated hydrocarbon is

(A) C2H6   

(B) C3H4   

(C) C2H2 

(D)  C2H4

Ans. : (A) C2H6

9. The molecular formula of three carbon compounds which are in homologous series are C2H6, C3H8, C4H10. The suitable general formula for these compounds is 

10. The functional groups present in propanol and propanal respectively are

(A) — OH  and  — CHO

(B) — OH  and  — COOH

(C) — CHO  and  — COOH

(D) — CHO  and  — CO

Ans:  (A) — OH  and  — CHO

11. The hydrocarbon that undergoes addition reaction among the following is 

A. C2 H6   

B. C3 H8    

C. CH4  

D. C3 H6

Ans: D. C3 H6

12.                                                                                                

13. Organic compounds obtained by the reaction between carboxylic acid and alcohol are 

(A) Aldehydes     

(B) Ketones

 

(C) Esters              

(D) Hydrocarbons

 

Ans. : (C) Esters 

14. The molecular formula of propanal is 

15. Correct statement related to the soaps among the following is, soaps 

(A) easily give excess of foam in hard water

 

(B) form insoluble precipitate in hard water

 

(C) easily clean oils like dirt in hard water

 

(D) are sodium salts of sulphonic acid 

Ans. : (B) form insoluble precipitate in hard water 

16. In a homologous series of compounds containing alcohols, the first member is CH3OH. Then the third member of the same series will be 

       BIOLOGY      

    LIFE PROCESESS   

1. An enzyme that secretes by the pancreas to digest protein is 

(A) amylase 

(B) pepsin 

(C) trypsin 

(D) lipase

Ans: (C) trypsin 

2. The correct statement regarding bile juice among the following is, this juice is secreted by the

(A) stomach and acidifies food. 

(B) stomach and alkalises food.

(C) liver and alkalises food. 

(D) pancreas and alkalises food.

Ans: (C) liver and alkalises food. 

3. The function of stomata among the following is 

(A) Exchange of gases

(B) Transportation of water and food

(C) Preparation of food

(D) Establishing osmotic pressure

Ans: (A) Exchange of gases

4. An incorrect statement related to the transpiration among the following is; this process

(A) Creates osmotic pressure for the movement of food molecules

(B) Helps in the absorption and movement of salts from the roots

(C) Creates suction force for the movement of water molecules

(D) Balances water level in a plant body

Ans: (A) Creates osmotic pressure for the movement of food molecules

5. A person runs immediately after seeing a snake, later experiences cramps in his leg muscles. Because, in the muscles 

(A) carbon dioxide and ethanol will form 

(B) pyruvate converts into lactic acid

(C) glucose is converted to pyruvate 

(D) amount of oxygen increases

Ans: (B) pyruvate converts into lactic acid