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JEE Advanced > Current Electricity

Explore popular questions from Current Electricity for JEE Advanced. This collection covers Current Electricity previous year JEE Advanced questions hand picked by experienced teachers.

Q 1.

Correct4

Incorrect-1

The temperature coefficient of resistance of a wire is {tex}0.00125 {/tex} per {tex} ^ { \circ } \mathrm { C } . {/tex} At {tex} 300 \mathrm { K } , {/tex} its resistance is {tex} 1 \mathrm { ohm } {/tex}. This resistance of the wire will be {tex} 2 \mathrm { ohm } {/tex} at.

A

{tex} 1154 \mathrm { K } {/tex}

B

{tex} 1100 \mathrm { K } {/tex}

C

{tex} 1400 \mathrm { K } {/tex}

{tex} 1127 \mathrm { K } {/tex}

Explanation

Q 2.

Correct4

Incorrect-1

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 halved.

both the length and the radius of the wire are doubled.

C

the radius of the wire is doubled.

D

the length of the wire is doubled.

Explanation

Q 3.

Correct4

Incorrect-1

The electrostatic field due to a point charge depends on the distance {tex} r {/tex} as {tex} \frac { 1 } { r ^ { 2 } } . {/tex} Indicate which of the following quantities shows same dependence on {tex} r . {/tex}

Intensity of light from a point source.

B

Electrostatic potential due to a point charge.

C

Electrostatic potential at a distancer from the centre of a charged metallic sphere. Given {tex} r < {/tex} radius of the sphere.

D

None of these

Explanation

Q 4.

Correct4

Incorrect-1

In the circuit shown in fig the heat produced in the 5 ohm resistor due to the current flowing through it is 10 calories per second.

The heat generated in the 4 ohms resistor is

A

1 calorie/ sec

2 calories / sec

C

3 calories / sec

D

4 calories / sec

Explanation

Q 5.

Correct4

Incorrect-1

The current i in the circuit (see Fig) is

A

{tex} \frac { 1 } { 45 } \mathrm { A } {/tex}

B

{tex} \frac { 1 } { 15 } \mathrm { A } {/tex}

{tex} \frac { 1 } { 10 } \mathrm { A } {/tex}

D

{tex} \frac { 1 } { 5 } \mathrm { A } {/tex}

Explanation

Q 6.

Correct4

Incorrect-1

A piece of copper and another of germanium are cooled from room temperature to {tex} 80 ^ { \circ } \mathrm { K } . {/tex} The resistance of

A

each of them increases

B

each of them decreases

C

copper increases and germanium decreases

copper decreases and germanium increases

Explanation

Q 7.

Correct4

Incorrect-1

A battery of internal resistance {tex} 4 \Omega {/tex} is connected to the network of resistances as shown. In order that the maximum power can be delivered to the network, the value of {tex} R {/tex} in {tex} \Omega {/tex} should be

A

{tex} \frac { 4 } { 9 } {/tex}

{tex}2{/tex}

C

{tex} \frac { 8 } { 3 } {/tex}

D

{tex}18{/tex}

Explanation


Q 8.

Correct4

Incorrect-1

In the circuit {tex} P \neq R , {/tex} the reading of the galvanometer is same with switch {tex} S {/tex} open or closed. Then

{tex} I _ { R } { = } I _ { G } {/tex}

B

{tex} I _ { P } = I _ { G } {/tex}

C

{tex} I _ { Q } = I _ { G } {/tex}

D

{tex} I _ { Q } = I _ { R } {/tex}

Explanation

Q 9.

Correct4

Incorrect-1

In the given circuit, with steady current, the potential drop across the capacitor must be

A

{tex} V {/tex}

B

{tex} V / 2 {/tex}

{tex} V / 3 {/tex}

D

{tex} 2 V / 3 {/tex}

Explanation


Q 10.

Correct4

Incorrect-1

A wire of length {tex} L {/tex} and {tex}3{/tex} identical cells of negligible internal resistances are connected in series. Due to the current, the temperature of the wire is raised by {tex} \Delta T {/tex} in a time {tex} t . {/tex} A number {tex} N {/tex} of similar cells is now connected in series with a wire of the same material and cross-section but of length {tex} 2 L . {/tex} The temperature of the wire is raised by the same amount {tex} \Delta T {/tex} in the same time {tex} t {/tex}. the value of {tex} N {/tex} is

A

4

6

C

8

D

9

Explanation


Q 11.

Correct4

Incorrect-1

In the given circuit, it is observed that the current {tex} I {/tex} is independent of the value of the resistance {tex} R _ { 6 } . {/tex} Then the resistance values must satisfy

A

{tex} R _ { 1 } R _ { 2 } R _ { 5 } = R _ { 3 } R _ { 4 } R _ { 6 } {/tex}

B

{tex} \frac { 1 } { R _ { 5 } } + \frac { 1 } { R _ { 6 } } = \frac { 1 } { R _ { 1 } + R _ { 2 } } + \frac { 1 } { R _ { 3 } + R _ { 4 } } {/tex}

{tex} R _ { 1 } R _ { 4 } = R _ { 2 } R _ { 3 } {/tex}

D

{tex} R _ { 1 } R _ { 3 } = R _ { 2 } R _ { 4 } = R _ { 5 } R _ { 6 } {/tex}

Explanation

Q 12.

Correct4

Incorrect-1

The effective resistance between points {tex} P {/tex} and {tex} Q {/tex} of the electrical circuit shown in the figure is

{tex} \frac { 2 R r } { R + r } {/tex}

B

{tex} \frac { 8 R ( R + r ) } { 3 R + r } {/tex}

C

{tex} 2 r + 4 R {/tex}

D

{tex} \frac { 5 R } { 2 } + 2 r {/tex}

Explanation

Q 13.

Correct4

Incorrect-1

A {tex} 100 \mathrm { W } {/tex} bulb {tex} B _ { 1 } , {/tex} and two {tex} 60 \mathrm { W } {/tex} bulb {tex} B _ { 2 } {/tex} and {tex} B _ { 3 } {/tex}, are connected to a {tex} 250 \mathrm { V } {/tex} source, as shown in figure. Now {tex} W _ { 1 }, {/tex} {tex} W _ { 2 } {/tex} and {tex} W _ { 3 } {/tex} are the output powers of the bulbs {tex} B _ { 1 } , B _ { 2 } {/tex} and {tex} B _ { 3 } {/tex} respectively. Then

A

{tex} W _ { 1 } > W _ { 2 } = W _ { 3 } {/tex}

B

{tex} W _ { 1 } > W _ { 2 } > \mathrm { W } _ { 3 } {/tex}

C

{tex} W _ { 1 } < W _ { 2 } = W _ { 3 } {/tex}

{tex} W _ { 1 } < W _ { 2 } < W _ { 3 } {/tex}

Explanation


Q 14.

Correct4

Incorrect-1

Express which of the following set ups can be used to verify Ohm's law?

B

C

D

Explanation



Q 15.

Correct4

Incorrect-1

In the shown arrangement of the experiment of the meter bridge if {tex} A C {/tex} corresponding to null deflection of galvanometer is {tex} x , {/tex} what would be its value if the radius of the wire {tex} A B {/tex} is doubled?

{tex} x {/tex}

B

{tex} x / 4 {/tex}

C

{tex} 4 x {/tex}

D

{tex} 2 x {/tex}

Explanation

Q 16.

Correct4

Incorrect-1

The three resistance of equal value are arranged in the different combinations shown below. Arrange them in increasing order of power dissipation.

{tex} \mathrm { III } < \mathrm { II } < \mathrm { IV } < \mathrm { I } {/tex}

B

{tex} \mathrm { II } < \mathrm { III } < \mathrm { IV } < \mathrm { I } {/tex}

C

{tex} \mathrm { I } < \mathrm { IV } < \mathrm { III } < \mathrm { II } {/tex}

D

{tex} \mathrm { I } < \mathrm { III } < \mathrm { II } < \mathrm { IV } {/tex}

Explanation


Q 17.

Correct4

Incorrect-1

Shown in figure is a Post Office box. In order to calculate the value of external resistance, it should be connected between

A

{tex} B ^ { \prime } {/tex} and {tex} C^{\prime} {/tex}

{tex} A {/tex} and {tex} D {/tex}

C

{tex} C {/tex} and {tex} D {/tex}

D

{tex} B {/tex} and {tex} D {/tex}

Explanation

Q 18.

Correct4

Incorrect-1

Six identical resistors are connected as shown in the figure. The equivalent resistance will be

A

Maximum between {tex} P {/tex} and {tex} R {/tex}

B

Maximum between {tex} Q {/tex} and {tex} R {/tex}

Maximum between {tex} \overrightarrow { { P } } {/tex} and {tex} { Q } {/tex}

D

All are equal

Explanation

Q 19.

Correct4

Incorrect-1

A capacitor is charged using an external battery with a resistance x in series. The dashed line shows the variation of ln I with respect to time. If the resistance is changed to {tex}2x{/tex}, the new graph will be

A

{tex} P {/tex}

{tex} { Q } {/tex}

C

{tex} R {/tex}

D

{tex} S {/tex}

Explanation