Wave Optics — Physics STD 12 Science — Question

Which of the following statements given below is not true in the context of magnetic lines of force?

Nuclear forces exists between:

The valence band and conduction band of a solid overlap at low temperature, the solid may be

(a) A metal

(b) A semiconductor

(c) An insulator

(d) None of these

Minimum excitation potential of Bohr's first orbit in hydrogen atom is

(a) 13.6 V

(b) 3.4 V

(c) 10.2 V

(d) 3.6 V

Radiations of two photon’s energy, twice and ten times the work function of metal are incident on the metal surface successsively. The ratio of maximum velocities of photoelectrons emitted in two cases is?

Which color band in the resistor is having highest tolerance?

The zone in a semiconductor diode where no free charge carriers exists is known as the:

When the key K is pressed at time  t = 0, which of the following statements about the current I in the resistor AB of the given circuit is true

(a) I = 2 mA  at all t

(b) I oscillates between 1 mA and 2mA

(c) I = 1 mA at all t

(d) At t = 0 , I = 2 mA and with time it goes to 1 mA

A magnet of magnetic moment M and pole strength m is divided in two equal parts, then magnetic moment of each part will be

(a) M

(b) M/2

(c) M/4

(d) 2M

Deviation of 5° is observed from a prism whose angle is small and whose refractive index is 1.5. The angle of prism is

(a) 7.5°

(b) 10°

(c) 5°

(d) 3.3°