List of top Physics Questions on Current electricity asked in JEE Main

Find the equivalent resistance between two ends of the following circuit:
equivalent resistance between two ends

Given below are two statements. One is labelled as Assertion (A) and the other is labelled as Reason (R):

Assertion (A): In an insulated container, a gas is adiabatically shrunk to half of its initial volume. The temperature of the gas decreases.
Reason (R): Free expansion of an ideal gas is an irreversible and an adiabatic process.

In the light of the above statements, choose the correct answer from the options given below:

Given below are two statements. One is labelled as Assertion (A) and the other is labelled as Reason (R): 
Assertion (A): In an insulated container, a gas is adiabatically shrunk to half of its initial volume. The temperature of the gas decreases. 
Reason (R): Free expansion of an ideal gas is an irreversible and an adiabatic process. \text{In the light of the above statements, choose the correct answer from the options given below:}


For the circuit shown above, the equivalent gate is:

 

Find the equivalent resistance between two ends of the following circuit: 
The circuit consists of three resistors, two of r3\frac{r}{3} in series connected in parallel with another resistor of rr.

In an ammeter, 5% of the main current passes through the galvanometer. If resistance of the galvanometer is G, the resistance of ammeter will be :
A wire of resistance R and radius r is stretched till its radius became r/2. If new resistance of the stretched wire is x R, then value of x is _________.
The ratio of heat dissipated per second through the resistance 5 ohm and 10 ohm in the circuit given below is :
Circuit diagram
Resistance of a wire at 0∘C0^\circ C, 100∘C100^\circ C and t∘Ct^\circ C is found to be 10 Ω10 \, \Omega, 10.2 Ω10.2 \, \Omega and 10.95 Ω10.95 \, \Omega respectively. The temperature tt in Kelvin scale is ______.
A potential divider circuit is connected with a dc source of 20 V, a light emitting diode of glow in voltage 1.8 V and a zener diode of breakdown voltage of 3.2 V. The length (PR) of the resistive wire is 20 cm. The minimum length of PQ to just glow the LED is …………. cm.
PR Circuit
A heater is designed to operate with a power of 1000 W in a 100 V line. It is connected in combination with a resistance of 10 Ω\Omega and a resistance RR, to a 100 V mains as shown in the figure. For the heater to operate at 62.5 W, the value of RR should be …\dots Ω\Omega.
heater
In the given circuit, the terminal potential difference of the cell is :
circuit
The equivalent resistance between A and B is:
Resistance Diagram
The current flowing through the 1Ω\Omega resistor is n10\frac{n}{10}A. The value of n is ________.
Resistance Diagram
In the experiment to determine the galvanometer resistance by half-deflection method, the plot of 1θ\frac{1}{ \theta} vs the resistance (R) of the resistance box is shown in the figure. The figure of merit of the galvanometer is .............. ×10–1 A/division. [The source has emf 2V]
Figure
In the given circuit, the voltage across load resistance (RL R_L ) is:

The voltage across a 5Ω resistor is given as V = 200 sin(100πt). Find out the time required for current through io it to change fromi02\frac{i_0}{2} to i0 [ i0 is peak current]

Wheatstone bridge principle is used to measure the specific resistance (S1) (S_1) of a given wire, having length L L , radius r r . If X X is the resistance of the wire, then specific resistance is: S1=X(πr2L). S_1 = X\left( \frac{\pi r^2}{L} \right). If the length of the wire gets doubled, then the value of specific resistance will be:
Two infinite current carrying wires having current I in opposite directions are shown below. 
Two infinite current carrying wires having current I in opposite directions
Find the magnetic field in S.I units, at point
Twelve wires, each having resistance 2 Ω 2 \, \Omega , are joined to form a cube. A battery of 6 V 6 \, \text{V} emf is joined across points a a and c c . The voltage difference between e e and f f is ______ V \text{V} .
The value of net resistance of the network as shown in the given figure is :
To measure the internal resistance of a battery, a potentiometer is used. For R=10 Ω R = 10 \, \Omega , the balance point is observed at ℓ=500 cm \ell = 500 \, \text{cm} and for R=1 Ω R = 1 \, \Omega , the balance point is observed at ℓ=400 cm \ell = 400 \, \text{cm} . The internal resistance of the battery is approximately:
In the given figure R1=10 Ω R_1 = 10 \, \Omega , R2=8 Ω R_2 = 8 \, \Omega , R3=4 Ω R_3 = 4 \, \Omega , and R4=8 Ω R_4 = 8 \, \Omega . The battery is ideal with an EMF of 12V.
The equivalent resistance of the circuit and the current supplied by the battery are respectively:
Circuit
The equivalent resistance of the following network is _____ Ω \Omega .
omega
Two conductors have the same resistances at 0∘C 0^\circ \text{C} but their temperature coefficients of resistance are α1 \alpha_1 and α2 \alpha_2 . The respective temperature coefficients for their series and parallel combinations are: