Electrostatic Potential and Capacitance — Physics STD 12 Science — Question

The energy that should be added to an electron to reduce its de Broglie wavelength from one nm to 0.5 nm is

(a) Four times the initial energy	(b) Equal to the initial energy
(c) Twice the initial energy	(d) Thrice the initial energy

Susceptibility is positive and large for a:

Hole in semiconductor is:

Corpuscular theory of light was advanced by:

The radius of hydrogen atom in its ground state is 5.3  . After collision with an electron it is found to have a radius of 21.2 . What is the principal quantum number n of the final state of the atom

(a) n = 4

(b) n = 2

(c) n = 16

(d) n = 3

Three resistances 4Ω each of are connected in the form of an equilateral triangle. The effective resistance between two corners is

(a) 8 Ω

(b) 12 Ω

(c)

(d)

Two cells of emfs approximately 5V and 10V are to be accurately compared using a potentiometer of length 400cm.

How can the rate of emission of electrons in a cathode ray tube can be increased?

Diode can work as:

In the given figure, an electron is moving from A to B. The direction of A induced current in the loop is: