Electromagnetic Waves — Physics STD 12 Science — Question

A particle is projected in a plane perpendicular to a uniform magnetic field. The area bounded by the path described by the particle is proportional to:

The ratio of the magnetic field at the centre of a current carrying circular wire and the magnetic field at the centre of a square coil made from the same length of wire will be

(a)

(b)

(c)

(d)

Photoelectric effect is the phenomenon in which?

If the de Broglie wavelength of a proton is 10⁻¹³m, the electric potential through which it must have been accelerated is:

A 10 V storage battery of negligible internal resistance is connected across a 50 Ω resistor. How much heat energy is produced in the resistor in 1 hour

(a) 7200 J

(b) 6200 J

(c) 5200 J

(d) 4200 J

A light ray is incident by grazing one of the face of a prism and after refraction ray does not emerge out, what should be the angle of prism while critical angle is C

(a) Equal to 2C

(b) Less than 2C

(c) More than 2C

(d) None of the above

Which of the following statement is not the true

(a) While taking reading of tangent galvanometer, the plane of the coil must be set at right angles to the earth’s magnetic meridian

(b) A short magnet is used in a tangent galvanometer since a long magnet would be heavy and may not easily move

(c) Measurements with the tangent galvanometer will be more accurate when the deflection is around 45o

(d) A tangent galvanometer can not be used in the polar region

At absolute zero temperature a crystal of pure germanium behaves as :

A circular loop carrying a current is replaced by an equivalent magnetic dipole. A point on the axis of the loop is in:

If a body is charged by rubbing it, its weight