Current Electricity — Physics STD 12 Science — Question

The angular spread of central maximum, in the diffraction pattern, does not depend on ______.

Assertion :   The stars twinkle while the planets do not.
Reason     :  The stars are much bigger in size than the planets.(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 current passes through a wire of non-uniform cross-section. Which of the following quantities are independent of the cross-section?

The radius of the convex surface of plano-convex lens is 20 cm and the refractive index of the material of the lens is 1.5. The focal length of the lens is(a) 30 cm(b) 50 cm(c) 20 cm(d) 40 cm

A ray of light travelling in a transparent medium falls on a surface separating the medium from air at an angle of incidence of 45°. The ray undergoes total internal reflection. If n is the refractive index of the medium with respect to air, select the possible value (s) of n from the following(a) 1.5(b) 1.6(c) 1.3(d) a, b

Shift by which the object appears to be raised depends on:

A horizontal circular loop carries a current that looks clockwise when viewed from above. It is replaced by an equivalent magnetic dipole consisting of a south pole S and a north pole N: