Atoms — Physics STD 12 Science — Question

An electron and proton have the same de-Broglie wavelength. Then the kinetic energy of the electron is

(a) Zero

(b) Infinity

(c) Equal to the kinetic energy of the proton

(d) Greater than the kinetic energy of the proton

If velocity of a particle is 3 times of that of electron and ratio of de brogile wavelength of particle to that of electron is 1.814×10⁻⁴. The particle will be:

The energy density in the electric field created by a point charge falls off with the distance from the point charge as:

What will be the equivalent resistance between the two points A and D

(a) 10 Ω

(b) 20 Ω

(c) 30 Ω

(d) 40 Ω

Order of  q/m  ratio of proton, α -particle and electron is

(a) e > p > α

(b) p > α > e

(c) e > α > p

(d) None of these

Two batteries, one of emf 18 volts and internal resistance 2Ω and the other of emf 12 volt and internal resistance 1 Ω, are connected as shown. The voltmeter V will record a reading of

(a) 15 volt

(b) 30 volt

(c) 14 volt

(d) 18 volt

Which of the following pairs has quantities of the same dimensions?

1. Magnetic field B and magnetizing field intensity H.
2. Magnetic field B and intensity of magnetization I.
3. Magnetizing field intensity H and intensity of magnetization I.
4. Longitudinal strain and magnetic susceptibility.

The S.I. unit of electric flux is

(a) Weber	(b) Newton per coulomb
(c) Volt  × metre	(d) Joule per coulomb

The Lyman transitions involve:

A beam of well collimated cathode rays travelling with a speed of 5   enter a region of mutually perpendicular electric and magnetic fields and emerge undeviated from this region. If |B| = 0.02T, the magnitude of the electric field is

(a)

(b) 2.5

(c) 1.25

(d) 2