Moving Charges and Magnetism — Physics STD 12 Science — Question

Number of electrons in one coulomb of charge will be

(a) 5.46

(b)  6.25

(c) 1.6

(d) 9

For which colour, the angle of deviation is maximum when light enters into glass from air?

As the quantum number increases, the difference of energy between consecutive energy levels?

In the arrangement of resistances shown below, the effective resistance between points A and B is

(a) 20 Ω

(b) 30 Ω

(c) 90 Ω

(d) 110 Ω

The electric field intensity at a point in vacuum is equal to:

The rate of change of magnetic flux density through a circular coil of area 10m and number of turns 100 is 10³ Wb/ m²/ s. The value of induced emf will be.

The figure shows the variation of photocurrent with anode potential for a photo-sensitive surface for three different radiations. Let   and  be the intensities and    and   be the frequencies for the curves a, b and c respectively

(a)  and	(b)  and
(c)  and	(d)  and

The frequency and intensity of a light source are both doubled. Consider the following statements.

1. The saturation photocurrent remains almost the same.
2. The maximum kinetic energy of the photoelectrons is doubled.

1. Both A and Bare true.
2. A is true but B is false.
3. A is false but B is true.
4. Both A and B are false.

The kinetic energy of an electron which is accelerated through a potential of 100 volts is

(a) 1.602

(b) 418.6 calories

(c) 1.16

(d) 6.626  W- sec

The figure represents the observed intensity of X-rays emitted by an X-ray tube as a function of wavelength. The sharp peaks A and B denote

(a) Band spectrum	(b) Continuous spectrum
(c) Characteristic radiations	(d) White radiations