Wave Optics — Physics STD 12 Science — Question

To get three images of a single object, one should have two plane mirrors at an angle of

(a) 30°

(b) 60°

(c) 90°

(d) 150°

The wavelength of radiation emitted is  when an electron jumps from the third to the second orbit of hydrogen atom. For the electron jump from the fourth to the second orbit of the hydrogen atom, the wavelength of radiation emitted will be

(a)

(b)

(c)

(d)

The kinetic energy force on the particle continuously increases with time.

1. The resultant force on the particle must be parallel to the velocity at all instants.
2. The resultant force on the particle must be at an angle less than 90° all the time.
3. Its height above the ground level must continuously decrease.
4. The magnitude of its linear momentum is increasing continuously.

Which rays are not the portion of electromagnetic spectrum

(a) X-rays

(b) Microwaves

(c) a-rays

(d) Radio waves

The ratio of the energy of an X-ray photon of wavelength 1 Å to that of visible light of wavelength 5000 Å  is

(a) 1: 5000

(b) 5000 : 1

(c) 1 :25  × 106

(d) 25 × 106

Which of the following is correct

(a) Ammeter has low resistance and is connected in series

(b) Ammeter has low resistance and is connected in parallel

(c) Voltmeter has low resistance and is connected in parallel

(d) None of the above

A spring-mass system oscillates with a frequency v. If it is taken in an elevator slowly accelerating upward, the frequency will:

1. Increase.
2. Decrease.
3. Remain same.
4. Become zero.

A flake of glass (refractive index 1.5) is placed over one of the openings of a double slit apparatus. The interference pattern displaces itself through seven successive maxima towards the side where the flake is placed. if wavelength of the diffracted light is λ = 600nm, then the thickness of the flake is

(a) 2100 nm

(b) 4200 nm

(c) 8400 nm

(d) None of these