JEE Physics - MCQ Practice Questions

In a Wheatstone bridge, if the four resistances are P, Q, R, and S connected in order, and the galvanometer shows zero deflection, which condition is satisfied?

An ideal ammeter connected in series with a circuit has resistance of:

A potential divider uses a 100 cm wire of total resistance 10Ω. A cell of EMF 2V and negligible internal resistance is connected across it. What is the potential gradient along the wire?

In a meter bridge experiment, when the null point is at 40 cm from the left end, the unknown resistance is found to be 20Ω. What is the standard resistance used?

A battery of EMF E and internal resistance r is connected to an external resistance R. The terminal voltage is:

In carbon resistors, color bands are used for identification. What does the third band represent?

A cylindrical conductor has resistance R. If it is melted and reformed into a wire of half its original length and half its original cross-sectional area, the new resistance will be:

The internal resistance of a Leclanche cell is approximately:

Two cells of EMF 1.5V each with internal resistances 0.5Ω are connected in series to an external resistance of 2Ω. What is the current in the circuit?

In a potentiometer, if the balancing length for a cell is 60 cm and for standard cell is 50 cm, what is the EMF of the unknown cell? (Standard cell = 1.018V)

An electric heater rated 500W, 250V is used for 4 hours daily. The energy consumed in one day is:

The equivalent resistance between two opposite corners of a cube made of 12 wires of 1Ω each is:

If the cross-sectional area of a wire is doubled while keeping length and material constant, how does resistivity change?

The temperature coefficient of resistance for a conductor is positive. This means:

A galvanometer with coil resistance 100Ω shows full-scale deflection at 10 mA. What shunt resistance is needed to convert it into an ammeter reading up to 1 A?

In a circuit with pure resistance, the phase difference between voltage and current is:

A rectangular conductor with dimensions 2cm × 3cm × 10cm is placed such that current flows through the 10cm length. If resistivity is 1.7 × 10⁻⁸ Ω·m, find the resistance:

A copper wire of length L and cross-sectional area A has resistance R. If the wire is stretched to double its length while maintaining the same volume, what is the new resistance?

In a circuit, three resistors of 2Ω, 3Ω, and 6Ω are connected in parallel. The equivalent resistance is:

A battery of EMF 12V and internal resistance 2Ω is connected to an external resistance of 4Ω. The current flowing through the circuit is: