NEET Physics Current Electricity MCQs Set A

Question: Consider a current carrying wire (current I) in the shape of a circle.
a) electric field produced by charges accumulated on the surface of wire
b) the charges just behind a given segment of wire which push them just the right way by repulsion
c) the charges ahead
d) source of emf
Answer: electric field produced by charges accumulated on the surface of wire

Question:

a)

b)

c)

d) None of these 

Answer:

Question:

a)

b)

c)

d)

Answer:

Question: Two cells of emfs approximately 5 V and 10 V are to be accurately compared using a potentiometer of length 400 cm
a) The battery of potentiometer can have a voltage of 15 V and R adjusted so that the potential drop across the wire slightly exceeds 10 V.
b) The first portion of 50 cm of wire itself should have a potential drop of 10 V.
c) Potentiometer is usually used for comparing resistances and not voltages
d) The battery that runs the potentiometer should have voltage of 8V
Answer: The battery of potentiometer can have a voltage of 15 V and R adjusted so that the potential drop across the wire slightly exceeds 10 V.

Question:

a)

b) maximum when the battery is connected across 10 cm × 1 cm faces
c)

d) same irrespective of the three faces
Answer:

Question: Which of the following characteristics of electrons determines the current in a conductor?
a) Drift velocity alone
b) Thermal velocity alone
c) Both drift velocity and thermal velocity
d) Neither drift nor thermal velocity
Answer:  Drift velocity alone

Question:

a) 19.2 kW
b) 19.2 J
c) 12.2 kW
d) 19.2 W
Answer:  19.2 kW

Question:

a) zero
b) 5 A
c) 2 A
d) 4 A
Answer: zero

Question: The cold junction of a thermocouple is maintained at 10ºC. No thermo e.m.f. is developed when the hot junction is maintained at 530ºC. The neutral temperature is
a) 270ºC
b) 260ºC
c) 265ºC
d) 520ºC
Answer: 270ºC

Question: In a large building, there are 15 bulbs of 40 W, 5 bulbs of 100 W, 5 fans of 80 W and 1 heater of 1 kW. The voltage of electric mains is 220 V. The minimum capacity of the main fuse of the building will be:
a) 12 A
b) 14 A
c) 10 A
d) 8 A
Answer:  12 A

Question:

a)

b)

c)

d)

Answer:

Question:  The equivalent resistance between A and B is

a)

b)

c)

d)

Answer:

More Questions.....................................................

Question:

a)

b)

c)

d)

Answer:

Question: Assertion : When current through a bulb decreases by 0.5%, the glow of bulb decreases by 1%.
Reason : Glow (Power) which is directly proportional to square of current.
a) If both Assertion and Reason are correct and Reason is the correct explanation of Assertion
b) If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion
c) If Assertion is correct but Reason is incorrect
d) If both the Assertion and Reason are incorrect
Answer: If both Assertion and Reason are correct and Reason is the correct explanation of Assertion

Question:  When 5V potential difference is applied across a wire of length 0.1 m, the drift speed of electrons is 2.5 × 10^–4 ms^–1. If the electron density in the wire is 8 × 10²⁸ m^–3, the resistivity of the material is close to :

a)

b)

c)

d)

Answer:

Question: A constant voltage is applied between the two ends of a uniform metallic wire. Some heat is developed in it. The heat developed is doubled if
a) both the length and the radius of the wire are doubled
b) the radius of the wire is doubled
c) the length of the wire is doubled.
d) both the length and the radius of the wire are halved
Answer:  both the length and the radius of the wire are doubled

Question:

a)

b)

c)

d)

Answer:

Question: A potentiometer wire is 100 cm long and a constant potential difference is maintained across it. Two cells are connected in series first to support one another and then in opposite direction. The balance points are obtained at 50 cm and 10 cm from the positive end of the wire in the two cases. The ratio of emf's is :
a) 3 : 2
b) 3 : 4
c) 5 : 4
d) 5 : 1
Answer: 3 : 2

Question:  A current source drives a current in a coil of resistance R₁ for a time t. The same source drives current in another coil of resistance R₂ for same time. If heat generated is same, find internal resistance of source.

a)

b)

c) zero
d) None of these
Answer:

Question:

a)

b)

c)

d)

Answer:

Question:

a) If Assertion is correct but Reason is incorrect
b) If both Assertion and Reason are correct and Reason is the correct explanation of Assertion
c) If both the Assertion and Reason are incorrect.
d) If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion
Answer: If Assertion is correct but Reason is incorrect

Question: Assertion : Bending a wire does not effect electrical resistance.
Reason : Resistance of wire is proportional ot resistivity of material
a) If both Assertion and Reason are correct and Reason is the correct explanation of Assertion
b) If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
c) If Assertion is correct but Reason is incorrect
d) If both the Assertion and Reason are incorrect
Answer:  If both Assertion and Reason are correct and Reason is the correct explanation of Assertion

Question:

a) 2 A
b) 4 A
c) 2.5A
d) None of these
Answer:  2 A

Question:

a) 6.798 × 10^–4 m/sec.
b) 67.98 × 10^–4 m/sec
c) 2.798 × 10^–4 m/sec
d) 0.67 × 10^–4 m/sec.
Answer: 6.798 × 10^–4 m/sec.

Question:  In the shown arrangement of the experiment of the meter bridge if AC corresponding to null deflection of galvanometer is x, what would be its value if the radius of the wire AB is doubled?

a) x
b) x /4
c) 2 x
d) 4 x
Answer:  x

Question:

a)

b)

c)

d)

Answer:

Question: The resistance of a wire is 'R' ohm. If it is melted and stretched to 'n' times its original length, its new resistance will be :

a)

b)

c)

d)

Answer:

Question: A potentiometer is an accurate and versatile device to make electrical measurements of E.M.F. because the method involves
a) A condition of no current flow through the galvanometer
b) A combination of cells, galvanometer and resistances
c) Cells
d) Potential gradients
Answer:  A condition of no current flow through the galvanometer

Question:

a) 0.13 A, from Q to P
b) 0.13 A, from P to Q
c) 1.3A from P to Q
d) 0A
Answer:  0.13 A, from Q to P

Question:

a) If Assertion is correct but Reason is incorrect
b) If both the Assertion and Reason are incorrect
c) If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion
d) If both Assertion and Reason are correct and Reason is the correct explanation of Assertion
Answer:  If Assertion is correct but Reason is incorrect

Question: Which of the following statements is false ?
a) In a balanced wheatstone bridge if the cell and the galvanometer are exchanged, the null point is disturbed.
b) Wheatstone bridge is the most sensitive when all the four resistances are of the same order of magnitude
c) Kirchhoff's second law represents energy conservation
d) A rheostat can be used as a potential divider
Answer: In a balanced wheatstone bridge if the cell and the galvanometer are exchanged, the null point is disturbed.

Question: In the circuit the current in each resistance is

a) 0 A
b) 1 A
c) 0.25 A
d) 0.5A
Answer:  0 A

Question: In the given circuit diagram when the current reaches steady state in the circuit, the charge on the capacitor of capacitance C will be :

a)

b)

c) CE

d)

Answer:

Question: A meter bridge is set up as shown, to determine an unknown resistance ‘X’ using a standard 10 ohm resistor. The galvanometer shows null point when tapping-key is at 52 cm mark. The end-corrections are 1 cm and 2 cm respectively for the ends A and B. The determined value of ‘X’ is

a) 10.6 ohm
b) 11.1 ohm
c) 10.2 ohm
d) 10.8 ohm
Answer:  10.6 ohm

Question:

a)

b)

c)

d)

Answer:

Question:  A wire is connected to a battery between the point M and N as shown in the figure (1). The same wire is bent in the form of a square and then connected to the battery between the points M and N as shown in the figure (2). Which of the following quantities increases ?

a) Heat produced in the wire and current through the wire
b) Heat produced in the wire, resistance offered by the wire and current through the wire
c) Resistance offered by the wire and current through the wire.
d) Heat produced in the wire and resistance offered by the wire
Answer:  Heat produced in the wire and current through the wire

Question:

a) Yellow – Violet – Orange – Silver
b) Green – Orange – Violet – Gold
c) Yellow – Green – Violet – Gold
d) Violet – Yellow – Orange – Silver
Answer: Yellow – Violet – Orange – Silver

Question: A set of 'n' equal resistors, of value 'R' each,are connected in series to a battery of emf 'E' and internal resistance 'R'. The current drawn is I. Now, the 'n' resistors are connected in parallel to the same battery. Then the current drawn from battery becomes 10 I. The value of'n' is
a) 10
b) 11
c) 9
d) 20
Answer: 10

Question:  A battery consists of a variable number 'n' of identical cells (having internal resistance 'r' each) which are connected in series. The terminals of the battery are short-circuited and the current I is measured. Which of the graphs shows the correct relationship between I and n?

a)

b)

c)

d)

Answer:

Question: Assertion : A current flows in a conductor only when thereis an electric field within the conductor.
Reason : The drift velocity of electron in presence of electric field decreases.
a) Assertion is correct, reason is incorrect
b) Assertion is incorrect, reason is correct
c) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
d) Assertion is correct, reason is correct; reason is a correct explanation for assertion.
Answer: Assertion is correct, reason is incorrect

Question:

a) 0.03 A P₂ to P₁
b) 0.27 A P₂ to P₁
c) 0.03 A P₁ to P₂
d) 0.27 A P₁ to P₂
Answer:  0.03 A P₂ to P₁

Question:  Two bulbs of 500 W and 200 W are manufactured to operate on 220 V line. The ratio of heat produced in 500 W and 200 W, in two cases, when firstly they are connected in parallel and secondary in series will be

a)

b)

c)

d)

Answer:

Question:

a)

b)

c)

d) None of these

Answer:

Question:

a) 11.5 V and 11.6 V
b) 11.7 V and 11.8 V
c) 11.6 V and 11.7 V
d) 11.4 V and 11.5 V
Answer:  11.5 V and 11.6 V

Question:

a)

b)

c)

d)

Answer:

Question:

a) 4/10 A
b) 1/10 A
c) 3/10 A
d) 7/10 A.
Answer:  4/10 A

Question:

a) 13.1 V
b) 11.9 V
c) 24.5 V
d) 12.5 V
Answer: 13.1 V

Question: Ten identical cells connected in series are needed to heat a wire of length one meter and radius ‘r’ by 10ºC in time ‘t’. How many cells will be required to heat the wire of length two meter of the same radius by the same temperature in time ‘t’?
a) 20
b) 30
c) 40
d) 10
Answer:  20

Question:

a)

b)

c)

d)

Answer:

Question:

a)

b)

c)

d)

Answer:

Question:  An electric heating element in vacuum is surrounded by a cavity at constant temperature of 227ºC; it consumes 60W of power to maintain a temperature of 727ºC. What is the power consumed by the element to maintain a temperature of 1227º C?
a) 320 W
b) 90 W
c) 304 W
d) 101 W
Answer: 320 W

Question:  In Fig. find the value of resistor to be connected between C and D, so that the resistance of the entire circuit between A and B does not change wth the number of elementary sets.

a)

b)

c) R
d) 3 R

Answer:

Question:  In the diagram shown, all the wires have resistance R. The equivalent resistance between the upper and lower dots shown in the diagram is

a) 3R/8
b) 2R/5
c) R
d) R/8
Answer:  3R/8

Question:

a)

b)

c)

d)

Answer:

Question: An electrical cable of copper has just one wire of radius 9 mm. Its resistance is 5 ohm. This single copper wire of the cable is replaced by 6 different well insulated copper wires each of radius 3 mm. The total resistance of the cable will now be equal to
a) 7.5 ohm
b) 45 ohm
c) 270 ohm
d) 90 ohm
Answer:  7.5 ohm

Question:

a)

b)

c)

d)

Answer:

Question:

a) 0.117 V
b) 0.00145 V
c) 0.0145 V
d) 1.7 × 10^–6 V
Answer:  0.117 V

Question:

a) 8/7 R
b) 2/7 R
c) 1/7 R
d) 4/7 R
Answer: 8/7 R

Question:  A hank of uninsulated wire consisting of seven and a half turns is stretched between two nails hammered into a board to which the ends of the wire are fixed. The resistance of the circuit between the nails is determined with the help of electrical measuring instruments. Determine the proportion in which the resistance will change if the wire is unwound so that the ends remain to be fixed to the nails.
a) 225
b) 15
c) 240
d) 250
Answer:  225

Question:

a) 6
b) 8
c) 9
d) 4
Answer:  6

Question:

a)

b)

c)

d)

Answer:

Question:

a) 8
b) 20
c) 10
d) 4
Answer:  8

Question:

a) 1.29 × 10^–4 m/s
b) 3.8 × 10^–3 m/s
c) 8.6 × 10^–4 m/s
d) 2.8 × 10^–2 m/s
Answer: 1.29 × 10^–4 m/s

Question:  The current density varies with radial distance r as J = a r², in a cylindrical wire of radius R. The current passing through the wire between radial distance R/3 and R/2 is

a)

b)

c)

d)

Answer:

Question: To get maximum current in a resistance of 3 ohms, one can use n rows of m cells (connected in series) connected in parallel. If the total number of cells is 24 and the internal resistance of a cell is 0.5 ohms then
a) m = 12, n = 2
b) m = 2, n = 12
c) m = 8, n = 3
d) m = 6, n = 4
Answer:  m = 12, n = 2