JEE Physics - MCQ Practice Questions

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

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:

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)

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?

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?

A wire of resistance 5Ω is bent into a square loop. What is the equivalent resistance between two adjacent corners?

In a Wheatstone bridge at balance, if P = 10Ω, Q = 20Ω, and R = 15Ω, then S equals:

Two resistors R₁ and R₂ are connected in series with a battery. If R₁ = 2R₂ and the voltage across R₁ is 8V, the voltage across R₂ is:

In a potentiometer experiment, the balancing length for a cell of EMF E is 75 cm. If another cell of EMF E/2 is used, the balancing length would be:

A meter bridge is balanced when the jockey is at 40 cm mark. If the known resistance is 12Ω, the unknown resistance is:

The EMF of a cell is 2V and its internal resistance is 0.5Ω. When connected to external resistance, the terminal voltage is 1.8V. The current in the circuit is:

When a conductor is heated, its resistance increases because:

A copper wire and an aluminum wire of same length and cross-sectional area carry the same current. Which has greater voltage drop?

Two resistors of 4Ω and 6Ω are connected in series with a 10V battery. The current through the circuit and power dissipated are respectively:

A wire of length L and cross-sectional area A has resistivity ρ. If the wire is stretched to double its length, what will be the new resistance?

A battery with EMF E and internal resistance r is connected to an external resistance R. What is the terminal voltage?

A potentiometer wire of length 100 cm has resistance 10Ω. A standard cell of EMF 1.5V is balanced at 40 cm. What is the EMF of an unknown cell if balanced at 65 cm?

In a circuit, the current through a 10Ω resistor is 2A. If this resistor is replaced by 5Ω, and the rest of the circuit remains unchanged, the new current will be: