JEE Physics - MCQ Practice Questions

If potential varies as V = 3x² + 4y in a region, the electric field at point (1,2) is:

A charged rod of length L with linear charge density λ is placed along the x-axis. The electric field at a point on the perpendicular bisector at distance y from the center is:

Two point charges Q and -Q are at distance 2d apart. The potential difference between two points on the perpendicular bisector at distances x and 2x from the midpoint is proportional to:

An insulating rod of length L is uniformly charged with total charge Q. The electric potential at a point on the axis at distance x from one end is:

A uniformly charged infinite line with linear charge density λ creates an electric field at perpendicular distance r. What is E?

Three point charges are arranged at the vertices of an equilateral triangle of side a. If charges are +q, +q, and -2q, what is the net electric potential at the centroid?

A charge Q is uniformly distributed on a ring of radius R. What is the electric potential at a point on the axis at distance x from the center?

Consider a uniformly charged disc of radius R with total charge Q. What is the electric field at the center of the disc?

Two point charges q₁ = 2 μC and q₂ = -2 μC are separated by 1 cm. What is the magnitude of electric field at the midpoint between them?

A spherical conductor of radius R is grounded and placed near an isolated point charge +Q at distance d from its center (d > R). Which statement is correct about the induced charge on the sphere?

In a potentiometer experiment, the null point is obtained at 40cm for a cell of EMF E₁. When a resistance of 5Ω is connected in series with the cell, the null point shifts to 30cm. The internal resistance of the cell is:

The sensitivity of a galvanometer can be increased by:

A wire of length L and cross-sectional area A has resistance R. If the wire is stretched to length 2L without change in volume, the new resistance will be:

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

A heating element of resistance R is connected to a battery of EMF E and internal resistance r. Maximum power is dissipated in R when:

Which of the following best explains why semiconductor resistance decreases with increase in temperature?

A battery of EMF 12V and internal resistance 2Ω is connected to a load resistance R. For maximum power transfer, R should be:

The electric field inside a copper conductor carrying current is approximately:

When a superconductor is cooled below its critical temperature, its resistance becomes zero. What is the effect on current flowing through it when connected to a constant voltage source?

The length of a conductor increases by 10% when stretched. Assuming volume remains constant, the resistance increases by approximately: