Magnetism And Matter — Physics STD 12 Science — Question

In N-type semiconductors, majority charge carriers are

(a) Holes

(b) Protons

(c) Neutrons

(d) Electrons

Two equal and opposite charges of 5 coulomb are kept mutually at a distance of 5.0 cm. The electric dipole moment of the system is :

The correct graph between the maximum energy of a photoelectron and the inverse of wavelength of the incident radiation is given by the curve

(a) A

(b) B

(c) C

(d) None of the above

Consider a mixture of oxygen and hydrogen kept at room temperature. AB compared to a hydrogen molecule an oxygen molecule hits the wall:

1. With greater average speed.
2. With smaller average speed.
3. With greater average kinetic energy.
4. With smaller average kinetic energy.

In the network of resistors shown in the adjoining figure, the equivalent resistance between A and B is

(a) 54 ohm

(b) 18 ohm

(c) 36 ohm

(d) 9 ohm

A small coil of N turns has area A and a current I flows through it. The magnetic dipole moment of this coil will be

(a) NI/A

(b)

(c)

(d) NIA

The time taken by sunlight to cross a 5 mm thick glass plate (μ = 3/2) is

(a) 0.25

(b) 0.167

(c) 2.5

(d) 1.0

X-rays region lies between

(a) Short radiowave and visible region	(b) Visible and ultraviolet region
(c) Gamma rays and ultraviolet region	(d) Short radiowave and long radiowave

Three equal positive charges are kept at the corners of an equilateral triangle. What will be the vector sum of the forces acting on the particles?