Wave Optics — Physics STD 12 Science — Question

X-rays are produced by accelerating electrons by voltage V and let they strike a metal of atomic number Z. The highest frequency of X-rays produced is proportional to

(a) V

(b) Z

(c) (Z – 1)

(d)

The transition of electron from n = 4, 5, 6, ………. to n = 3 corresponds to:

The largest distance between the interatomic planes of a crystal is 10^-7cm. The upper limit for the wavelength of X-rays which can be usefully studied with this crystal is

(a) 1 Å

(b) 2 Å

(c) 10 Å

(d) 20 Å

 Identify the conclusion of the photoelectric experiment from the following.

The process by which ac is converted into dc is known as:

Two wires A and B of same material and same mass have radius 2rand r. If resistance of wire A is 34 Ω, then resistance of B will be

(a) 544 Ω

(b) 272 Ω

(c) 68 Ω

(d) 17 Ω

A free charged particle moves through a magnetic field. The particle may undergo a change in:

If in a photoelectric experiment, the wavelength of incident radiation is reduced from 6000 Å to 4000 Å then

(a) Stopping potential will decrease

(b) Stopping potential will increase

(c) Kinetic energy of emitted electrons will decrease

(d) The value of work function will decrease

Shows the elliptical path of a planet about the sun. The two shaded parts have equal area. If t₁ and t₂ be the time taken by the planet to go from a to b and from c to d respectively:

1. t₁ < t₂
2. t₁ = t₂
3. t₁ > t₂
4. Insufficient information to deduce the relation between t₁ and t₂.

A rod of length 20 cm is rotating with angular speed of 100 rps in a magnetic field of strength 0.5 T about it’s one end. What is the potential difference between two ends of the rod

(a) 2.28 V

(b) 4.28 V

(c) 6.28 V

(d) 2.5 V