Current Electricity - Electricity - Physics Previous Year Questions

1

2016 · Physics · Electricity · Current Electricity

WB JEE 2016

Two wires of same radius having lengths l₁ and l₂ and resistivities \({{\rho _1}}\) and \({{\rho _2}}\) are connected in series. The equivalent resistivity will be

A

\({{{\rho _1}{l_2} + {\rho _2}{l_1}} \over {{\rho _1} + {\rho _2}}}\)

B

\({{{\rho _1}{l_1} + {\rho _2}{l_2}} \over {{l_1} + {l_2}}}\)

C

\({{{\rho _1}{l_1} - {\rho _2}{l_2}} \over {{l_1} - {l_2}}}\)

D

\({{{\rho _1}{l_2} + {\rho _2}{l_1}} \over {{l_1} + {l_2}}}\)

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2

2016 · Physics · Electricity · Current Electricity

WB JEE 2016

The effective resistance between A and B in the figure is \({7 \over {12}}\Omega\) if each side of the cube has 1\(\Omega\) resistance. The effective resistance between the same two points, when the link AB is removed, is

A

\({7 \over {12}}\Omega\)

B

\({5 \over {12}}\Omega\)

C

\({7 \over {5}}\Omega\)

D

\({5 \over {7}}\Omega\)

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3

2016 · Physics · Electricity · Current Electricity

WB JEE 2016

Two equal resistances, 400 \(\Omega\) each, are connected in series with a 8 V battery. If the resistance of first one increases by 0.5%, the change required in the resistance of the second one in order to keep the potential difference across it unaltered is to

A

increase it by 1\(\Omega\)

B

increase it by 2\(\Omega\)

C

increase it by 4\(\Omega\)

D

decrease it by 4\(\Omega\)

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4

2017 · Physics · Electricity · Current Electricity

WB JEE 2017

Consider the circuit shown in the figure where all the resistances are of magnitude 1 k\(\Omega\). If the current in the extreme right resistance X is 1 mA, the potential difference between A and B is

A

34 V

B

21 V

C

68 V

D

55 V

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5

2017 · Physics · Electricity · Current Electricity

WB JEE 2017

Consider the circuit given here. The potential difference V_BC between the points B and C is

A

1 V

B

0.5 V

C

0 V

D

\(-\) 1 V

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6

2017 · Physics · Electricity · Current Electricity

WB JEE 2017

Consider the circuit shown in the figure.


The value of the resistance X for which the thermal power generated in it is practically independent of small variation of its resistance is

A

X = R

B

X = \({R \over 3}\)

C

X = \({R \over 2}\)

D

X = 2R

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7

2017 · Physics · Electricity · Current Electricity

WB JEE 2017

Six wires, each of resistance r, are connected so as to form a tetrahedron. The equivalent resistance of the combination when current enters through one corner and leaves through some other corner is

A

r

B

2r

C

\({r \over 3}\)

D

\({r \over 2}\)

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8

2018 · Physics · Electricity · Current Electricity

WB JEE 2018

Four resistors, 100\(\Omega\), 200\(\Omega\), 300\(\Omega\) and 400\(\Omega\) are connected to form four sides of a square. The resistors can be connected in any order. What is the maximum possible equivalent resistance across the diagonal of the square?

A

210\(\Omega\)

B

240\(\Omega\)

C

300\(\Omega\)

D

250\(\Omega\)

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9

2018 · Physics · Electricity · Current Electricity

WB JEE 2018

What will be current through the 200\(\Omega\) resistor in the given circuit, a long time after the switch K is made on?

A

Zero

B

100 mA

C

10 mA

D

1 mA

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10

2018 · Physics · Electricity · Current Electricity

WB JEE 2018

An electric bulb, a capacitor, a battery and a switch are all in series in a circuit. How does the intensity of light vary when the switch is turn on?

A

continues to increase gradually

B

gradually increases for sometime and then becomes steady

C

sharply rises initially and then gradually decreases

D

gradually increases for sometime and then gradually decreaes.

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11

2018 · Physics · Electricity · Current Electricity

WB JEE 2018

A non-zero current passes through the galvanometer G shown in the circuit when the key K is closed and its value does not change when the key is opened. Then, which of the following statement(s) is/are true?

A

the galvanometer resistance is infinite.

B

the current through the galvanometer is 40 mA.

C

After the key is closed, the current through the 200\(\Omega\) resistor is same as the current through the 300\(\Omega\) resister.

D

The galvanometer resistance is 150\(\Omega\)

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12

2019 · Physics · Electricity · Current Electricity

WB JEE 2019

In the circuit shown in the figure all the resistance are identical and each has the value r\(\Omega\). The equivalent resistance of the combination between the points A and B will remain unchanged even when the following pairs of points marked in the figure are connected through a resistance R.

A

2 and 6

B

3 and 6

C

4 and 7

D

4 and 6

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13

2019 · Physics · Electricity · Current Electricity

WB JEE 2019

What is the current I shown in the given circuit?

A

\({V \over {2R}}\)

B

\({V \over {R}}\)

C

\({V \over {16R}}\)

D

\({V \over {8R}}\)

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14

2019 · Physics · Electricity · Current Electricity

WB JEE 2019

Five identical capacitors, of capacitance 20\(\mu\)F each, are connected to a battery of 150V, in a combination as shown in the diagram. What is the total amount of charge stored?

A

\(15 \times {10^{ - 3}}C\)

B

\(12 \times {10^{ - 3}}C\)

C

\(10 \times {10^{ - 3}}C\)

D

\(3 \times {10^{ - 3}}C\)

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15

2019 · Physics · Electricity · Current Electricity

WB JEE 2019

When the value of R in the balanced Wheatstone bridge, shown in the figure, is increased from 5\(\Omega\) to 7\(\Omega\), the value of S has to be increased by 3\(\Omega\) in order to maintain the balance. What is the initial values of S?

A

2.5\(\Omega\)

B

3\(\Omega\)

C

5\(\Omega\)

D

7.5\(\Omega\)

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16

2019 · Physics · Electricity · Current Electricity

WB JEE 2019

A capacitor of capacitance C is connected in series with a resistance R and DC source of emf E through a key. The capacitor starts charging when the key is closed. By the time the capacitor has been fully charged, what amount of energy is dissipated in the resistance R?

A

\({1 \over 2}C{E^2}\)

B

0

C

CE²

D

\({{{E^2}} \over R}\)

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17

2020 · Physics · Electricity · Current Electricity

WB JEE 2020

What will be the equivalent resistance between the terminals A and B of the infinite resistive network shown in the figure?

A

\({{\left( {\sqrt 3 + 1} \right)R} \over 2}\)

B

\({{\left( {\sqrt 3 - 1} \right)R} \over 2}\)

C

\(3{R \over 2}\)

D

\({\left( {\sqrt 3 + 1} \right)R}\)

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18

2020 · Physics · Electricity · Current Electricity

WB JEE 2020

A galvanometer can be converted to a voltmeter of full scale deflection V₀ by connecting a series resistance R₁ and can be converted to an ammeter of full scale deflection I₀ by connecting a shunt resistance R₂. What is the current flowing through the galvanometer at its full scale deflection?

A

\({{{V_0} - {I_0}{R_2}} \over {{R_1} - {R_2}}}\)

B

\({{{V_0} + {I_0}{R_2}} \over {{R_1} + {R_2}}}\)

C

\({{{V_0} - {I_0}{R_1}} \over {{R_2} - {R_1}}}\)

D

\({{{V_0} + {I_0}{R_1}} \over {{R_1} + {R_2}}}\)

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19

2020 · Physics · Electricity · Current Electricity

WB JEE 2020

Consider the circuit shown.


If all the cells have negligible internal resistance, what will be the current through the 2\(\Omega\) resistor when steady state is reached?

A

0.66 A

B

0.29 A

C

0 A

D

0.14 A

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20

2021 · Physics · Electricity · Current Electricity

WB JEE 2021

The carbon resistor with colour code is shown in the figure. There is no fourth band in the resistor. The value of the resistance is

A

24 M\(\Omega\) \(\pm\) 20%

B

14 k\(\Omega\) \(\pm\) 5%

C

24 k\(\Omega\) \(\pm\) 20%

D

34 k\(\Omega\) \(\pm\) 10%

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