Atoms — Physics STD 12 Science — Question

When a photon stimulates the emission of another photon, the two photons have:

A conducting rod of length L is falling with velocity v perpendicular to a uniform horizontal magnetic field B. The potential difference between its two ends will be.

The back e.m.f. induced in a coil, when current changes from 1 ampere to zero in one milli‑second, is 4 volts, the self inductance of the coil is

(a) 1 H

(b) 4 H

(c)  H

(d) 4  H

Two sound waves move in the same direction in the same medium. The pressure amplitudes of the waves are equal but the wavelength of the first wave is double the second. Let the average power transmitted across a cross-section by the first wave be P₁ and that by the 1 second wave be P₂. Then,

1. P₁ = P₂
2. P₁ = 4P₂
3. P₂ = 2P₁
4. P₂ = 4P₁

If one of the two slits of Young's double-slit experiment is painted so that it transmits half the light intensity as the second slit, then:

The work done by the external force in bringing the charge q from infinity to a point is called as:

By placing the prism in minimum deviation position, images of the spectrum

(a) Becomes inverted

(b) Becomes broader

(c) Becomes distinct

(d) Becomes intensive

The half-life of radon is 3.8 days. Three forth of a radon sample decay in

(a) 5.02 days

(b) 15.2 days

(c) 7.6 days

(d) 11.4 days

K_α  wavelength emitted by an atom of atomic number Z = 11 is λ. Find the atomic number for an atom that emits K_α radiation with wavelength 4l

(a) Z = 6

(b) Z = 4

(c) Z = 11

(d) Z = 44