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YPM/CHAPTERWISE MCQ : CURRENT ELECTRICITY

CHAPTER WISE MCQ

CHAPTER: CURRENT ELECTRICITY

1. Two resistors A and B have resistances 𝑹𝑨 and 𝑹𝑩

respectively such that 𝑹𝑨 > 𝑹𝑩 . the resistivity of

their materials are 𝝆𝑨 and 𝝆𝑩

(1) 𝜌𝐴 > 𝜌𝐵 (2) 𝜌𝐴 = 𝜌𝐵

(3) 𝜌𝐴 < 𝜌𝐵 (4) given data is not sufficient

2. The product of resistivity and conductivity of

cylindrical conductor depends on

(1) temperature (2) material

(3) area of cross section (4) none of these

3. As temperature of a metallic resistor is increased,

the product of its resistivity and conductivity

(1) increases (2) decreases

(3) remains constant (4) may increase or decrease

4. In an electrical circuit containing a battery, the

positive charge inside the battery

(1) always goes from the positive terminal to the

negative terminal

(2) may go from positive terminal to the negative

terminal

(3) always go from negative terminal to the positive

terminal

(4) does not move

5. A resistor of resistance R is connected to an ideal

battery. If the value of R is decreased, the power

dissipated in the resistor will be

(1) increase (2) decrease

(3) remains unchanged (4) fluctuate

6. The current passes through a resistor. Let

𝑲𝟏 𝒂𝒏𝒅 𝑲𝟐 represent average kinetic energy of

the conduction electrons and metal ions

respectively

(1) 𝐾1 < 𝐾2 (2) 𝐾1 = 𝐾2

(3) 𝐾1 > 𝐾2 (4) any of these three may occur

7. A uniform wire of resistance 50 Ω is cut into five

equal parts. These parts are now connected in

parallel. The equivalent resistance of the

combination is

(1) 2 Ω (2) 10 Ω

(3) 250 Ω (4) 6250 Ω

8. Consider following two statements

(A) Kirchhoff’s junction law follows from

conservation of charge.

(B) Kirchhoff’s loop law follows from conservative

nature of electric field

(1) both A and B are correct

(2) A is correct but B is wrong.

(3) B is correct but A is wrong

(4) both A and B are wrong

9. Two non-ideal batteries are connected in series.

Consider the following statements

(A) the equivalent emf is larger than either of the

two emfs

(B) the equivalent internal resistance is smaller than

either of the two internal resistances





10. Two non-ideal batteries are connected in

parallel. Consider the following statements

(A) the equivalent emf is smaller than either of the

two emfs

(B) the equivalent internal resistance is smaller

than either of the two internal resistances





11. Which of the following quantities do not change

when a resistor connected to a battery is heated

due to the current?

(1) drift speed (2) resistivity

(3) resistance (4) number of free electron

12. As the temperature of a conductor increases, its

resistivity and conductivity change. The ratio of

resistivity to conductivity

(1) incrases (2) decreases

(3) remains constant

(4) may increase or decrease

depending on the actual temperature.

13. The belt of an electrostatic generator is 50 cm

wide and travels 30 cm/s. The belt carries charge

in to the sphere at a rate corresponding to

𝟏𝟎−𝟒𝑨. What is the surface density of charge on

the belt

(1) 6.7 × 10−5 𝐶

𝑚2 (2) 6.7 × 10−4 𝐶

𝑚2

(3) 6.7 × 10−7 𝐶

𝑚2 (4) 6.7 × 10−8 𝐶

𝑚2

14. Two wires of the same materials but different

diameters carry the same current I. if the ratio of

its diameters is 2 : 1, then the corresponding

ratio of their mean drift velocities will be

(1) 4 : 1 (2) 1 : 1

(3) 1 : 2 (4) 1: 4


15. There are two concentric spheres of radius a and

b respectively. If the space between them is filled

medium of resistivity 𝝆. Then the resistance of

the intergap between the two sphere will be

(1) 𝜌

4𝜋(𝑏+𝑎) (2)

𝜌

4𝜋[

1

𝑏 −

1

𝑎]

(3) 𝜌

4𝜋[

1

𝑎2 − 1

𝑏2] (4) 𝜌

4𝜋[

1

𝑎 −

1

𝑏]

16. Masses of three wires of same materials are in

the ratio of 1 : 2 : 3 and their lengths are the

ratio of 3 : 2 : 1 . Electrical resistances of these

wires will be in the ratio of

(1) 1 : 1 : 1 (2) 1 : 2 : 3

(3) 9 : 4 : 1 (4) 27 : 6 : 1

17. The graph represents current- voltage behaviour

of water voltmeter figure spot the correct

explanation.

(1) electrolytes do not obey Ohm’s law

(2) Ohm’s law is not valid for low voltage

(3) dissociation takes place at E and it obeys

Ohm’s law there after

(4) Ohm’s law is obeyed but only for potential

difference larger than the back emf

18. The equivalent resistance of n resistors each of

same resistances when connected in series is R. If

the same resistances are connected in parallel

the equivalent resistance will be

(1) 𝑅

𝑛2 (2) 𝑅

𝑛

(3) 𝑛2𝑅 (4) 𝑛𝑅

19. An infinite ladder network of resistances is

constructed with 1 Ω and 2 Ω resistances as

shown in the fig. The 6V battery between A and

B has negligible internal resistance than effective

resistance between A and B is

(1) 3 Ω (2) 2 Ω (3)

6/5 Ω (4) 5/6 Ω

20. In the circuit shown in the figure, the point F is

grounded. Which of the following is wrong

statement?

(1) D point is at 5 volt

(2) point E is at zero potential

(3) the current in the circuit will be 0.5 A

(4) point C is at 3 volt

21. In the circuit in figure the potential difference

across P and Q will be nearest to

(1) 9.6 V (2) 6.6 V

(3) 4 V (4) 3.2 V

22. The length of potentiometer wire is 5 m. An

electron in this wire experiences a force of 𝟒. 𝟖 ×

𝟏𝟎−𝟏𝟗 N , emf of main cell used in potentiometer

is

(1) 3 V (2) 15 V

(3) 1.5 V (4) 5 V

23. In the potentiometer of 10 wires, the balance

point is obtained on the 7th wire. To shift the

balance point to 9th wire, we should

(1) decrease resistance in the main circuit

(2) increase resistance in the main circuit

(3) decrease resistance in series with the cell

whose emf is to be measured

(4) increase resistance in series with the cell

whose emf is to be determined

24. What is the potential difference between points

A and D of circuit shown in the figure?

(1) 5 V (2) 9 V


(3) 10.4 V (4) 11.4 V

25. The V-I graph for a conductor at temperature

𝑻𝟏 𝒂𝒏𝒅 𝑻𝟐 are shown in the figure. The term

𝑻𝟏 − 𝑻𝟐 is proportional to

(1) cos 2𝜃 (2) sin 2𝜃

(3) cot 2𝜃 (4) tan 2𝜃

26. A 6 V battery is connected to the terminals of a

three metre long wire of uniform thickness and

resistance of 100Ω. The difference of potential

between two points on the wire separated by a

distance of 50 cm will be

(1) 2 V (2) 3 V

(3) 1 V (4) 1.5 V

27. The resistance of wire is 5 Ω at 50°C and 6 Ω at

100°C . The resistance of the wire at 0° C will be

(1) 2 Ω (2) 1 Ω

(3) 4 Ω (4) 3 Ω

28. A material B has twice the specific resistance of

A. A circular wire made of B has twice the

diameter of wire made of A. Then for the two

wires to have same resistance, the ratio 𝑳𝑩

𝑳𝑨 of

their respective lengths must be

(1) 1 (2) 1/2

(3) 1/4 (4) 2

29. An electric bulb is rated 220 V – 100 W . The

power consumed by it when operated on 110 V

will be

(1) 75 W (2) 40 W

(3) 25 W (4) 50 W

30. The resistance of bulb filament is 100 Ω at

temperature of 100°C. If its temperature

coefficient of resistance be 0.005 per °𝑪 its

resistance will become 200 Ω at temperature of

(1) 300°𝐶 (2) 400°𝐶

(3) 500°𝐶 (4) 200°𝐶

31. The current I drawn from the 5 V source will be

(1) 0.33 A (2) 0.5 A

(3) 0.67 A (4) 0.17 A

32. A rigid container with thermally insulated walls

contains a coil of resistance 100 Ω, carrying

current 1 A. Change in internal energy after 5

min. will be

(1) zero (2) 10 kJ

(3) 20 kJ (4) 30 kJ

33. In the circuit, the galvanometer G shows zero

deflection. If the batteries A and B have

negligible internal resistance, the value of

resistor R will be

(1) 200 Ω (2) 100 Ω

(3) 500 Ω (4) 1000 Ω

34. The energy source will supply a constant current

into the load. If the internal resistance is

(1) equal to the resistance of the load

(2) very large as compare to the load resistance

(3) zero

(4) nonzero but less than the resistance of the

load

35. Time taken by a 836 W heater to heat one litre of

water from 10°C to 40°C is

(1) 50 s (2) 100 s

(3) 150 s (4) 200 s

36. The length of wire of a potentiometer is 100 cm,

and the emf of its cell is E volt. It is employed to

measure the emf of battery whose internal

resistance is 0.5 Ω. If the balance point is

obtained at l = 30 cm from the positive end, the

emf of the battery is (I is current in the

potentiometer wire)

(1) 30 𝐸

100.5 (2)

30𝐸

100−0.5 (3)

30(𝐸−0.5𝐼)

100 (4)

30 𝐸

100


37. In the adjoining circuit, the equivalent resistance

between the point A and B is

(1) (√2 − 1)Ω (2) (√2 + 1)Ω (3)

(√3 − 1)Ω (4) (√3 + 1)Ω

38. The potential gradient along the potentiometer

wire shown in the figure is

(1) 1.0 V/m (2) 0.1 V/m (3)

0.5 V/m (4) 0.05 V/m

39. The P. D. across points B and C is balanced at 40

cm length of the potentiometer wire X and Y in

the given circuit. To balance the P.D. across A

and D, at what distance from X, the jockey K will

have to be touched on the wire?

(1) 60 cm (2) 72 cm (3) 40

cm (4) 65 cm

40. Resistivity of wire of length L and area of cross

section A varies with distance x from the origin

end as = 𝜶 + 𝜷𝒙 , where 𝜶 𝒂𝒏𝒅 𝜷 are constants.

What is the total resistance of the wire?

(1) 𝐿

𝐴(𝛼 + 𝛽𝐿) (2)

𝐿

𝐴(𝛼 +

𝛽𝐿

2)

(3) 𝐿

𝐴𝛼 (4)

𝐿

𝐴(𝛼 + 𝛽)

41. Resistance of two wires at temperature 𝜽 is as

𝑹𝟏 = 𝟑 + 𝟒𝜽 and 𝑹𝟐 = 𝟒 + 𝟑𝜽. Now wires are

connected in series then temperature co-efficient

of resistance of series combination is

(1) 1 (2) 2

(3) 7 (4) 12

42. N wires of same length and same area but of

different resistivities, 𝝆𝟏, 𝝆𝟐, 𝝆𝟑 ……………..𝝆𝑵 are

connected in series. The resistivity of composite

wire is

(1) 𝜌1+ 𝜌2+ 𝜌3+ ……………..+𝜌𝑁

𝑁

(2) (𝜌1 𝜌2 𝜌3 … … … … … . . 𝜌𝑁)1/𝑁

(3) (𝜌1 𝜌2 𝜌3 ……………..𝜌𝑁)1/𝑁

𝑁

(4) 𝜌1 + 𝜌2 + 𝜌3 + … … … … … . . +𝜌𝑁

43. You have three copper wires of lengths ratio 𝒙 ∶

𝒚 ∶ 𝒛 and mass ratio 𝒙𝒛 ∶ 𝒛𝒙 ∶ 𝒙𝒚 then ratio of

their resistances is

(1) 𝑥 ∶ 𝑦 ∶ 𝑧 (2) 𝑥2 ∶ 𝑦2 ∶ 𝑧2

(3) 𝑥3 ∶ 𝑦3 ∶ 𝑧3 (4) 𝑥1/2 ∶ 𝑦1/2 ∶ 𝑧1/2

44. Charge passing from a section of wire is depends

on tome as 𝑸 = 𝜶𝒕𝟐 − 𝜷𝒕 where 𝜶 𝒂𝒏𝒅 𝜷 are

constant. If current at instant 𝒕𝟏 𝒂𝒏𝒅 𝒕𝟐 are

𝑰𝟏 𝒂𝒏𝒅 𝑰𝟐 then (𝑰𝟏 − 𝑰𝟐) is proportional to

(1) (𝑡1 − 𝑡2) (2) (𝑡1 − 𝑡2)2

(3) (𝑡12 − 𝑡2

2) (4) constant

45. A part of circuit is as shown in the figure

potential at centre point is

(1) 𝑉1+𝑉2 +𝑉3+𝑉4

4 (2) zero

(3) 𝑉1 + 𝑉2 + 𝑉3 + 𝑉4 (4) 𝑉1+𝑉2 +𝑉3+𝑉4

4𝑅


ANSWER KEY

1 2 3 4 5 6 7 8 9 10

4 4 3 3 1 3 2 1 2 3

11 12 13 14 15 16 17 18 19 20

4 1 2 4 4 4 1 1 2 2

21 22 23 24 25 26 27 28 29 30

4 2 4 3 3 3 3 3 3 2

31 32 33 34 35 36 37 38 39 40

2 4 2 3 3 4 4 1 2 2

41 42 43 44 45

1 1 3 1 1

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