Moving Charges and Magnetism — Physics STD 12 Science — Question

In an AC circuit, the impedance is 3​ times the reactance, then the phase angle is.

The value of force along on a charged particle in electric tied is :

The light when enters the human eye experiences most of the refraction while passing through

(a) Cornea

(b)  Aqueous humour

(c) Vitrous humour

(d)  Crystalline lens

When light falls on a metal surface, the maximum kinetic energy of the emitted photo-electrons depends upon

(a) The time for which light falls on the metal

(b) Frequency of the incident light

(c) Intensity of the incident light

(d) Velocity of the incident light

Assertion :   Magnetic field interacts with a moving charge and not with a stationary charge.

Reason    : A moving charge produces a magnetic field.

(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.

(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.

(c) If assertion is true but reason is false.

(d) If the assertion and reason both are false.

A positively charged particle projected towards east is deflected towards north by a magnetic field. The field may be:

The ratio of the energy of a photon with   to that with   is

(a) 2

(b) 1/4

(c) 4

(d) 1/2

Two thick wires and two thin wires, all of the same materials and same length form a square in the three different ways P, Q and R as shown in fig with current connection shown, the magnetic field at the centre of the square is zero in cases

(a) In P only

(b) In P and Q only

(c) In Q and R only

(d)  P and R only

A beam of light of wavelength λ  and with illumination L falls on a clean surface of sodium. If N photoelectrons are emitted each with kinetic energy E, then

(a) N ∝ L  and E ∝ L	(b)  N ∝ L and E ∝
(c) N ∝   and E ∝ L	(d) N ∝   and E ∝

The electric field at the origin is along the positive x-axis. A small circle is drawn with the centre at the origin cutting the axes at points A, B, C and D having coordinates (a, 0), (0, a), (-a, 0), (0, -a) respectively. Out of the points on the periphery of the circle, the potential is minimum at.