MCQ
In Davison-Germer experiment, an electron beam is incident on a crystal. The reflected beam consists of:
  • A
    Photon.
  • B
    Protons.
  • C
    X-rays.
  • D
    Electrons.

Answer

  1. Electrons.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

The process of superimposing signal frequency (i.e. audio wave) on the carrier wave is known as

(a) Transmission

(b) Reception

(c) Modulation

(d) Detection

In a parallel plate condenser, the radius of each circular plate is 12 cm  and the distance between the plates is 5mm. There is a glass slab of 3mm  thick and of radius 12 cm  with dielectric constant 6 between its plates. The capacity of the condenser will be

(a) 144  

(b) 40 pF

(c) 160 pF

(d) 1.44 μF

Assertion :   The threshold frequency of photoelectric effect supports the particle nature of sunlight.

Reason      : If frequency of incident light is less than the threshold frequency, electrons are not emitted from metal surface.

(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.

(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.

(c) If assertion is true but reason is false.

(d) If the assertion and reason both are false.

Angle of prism is A and its one surface is silvered. Light rays falling at an angle of incidence 2A on first surface return back through the same path after suffering reflection at second silvered surface. Refractive index of the material of prism is

(a) 2 sin A

(b) 2 cos A

(c)  

(d) tan A

Magnetic lines of force due to a bar magnet do not intersect because:
Gravitational force has only on sign but coulomb force has:

Fusion reaction takes place at high temperature because

(a) Atoms are ionised at high temperature

(b) Molecules break-up at high temperature

(c) Nuclei break-up at high temperature

(d) Kinetic energy is high enough to overcome repulsion between nuclei

An object is placed 40 cm  from a concave mirror of focal length 20 cm  The image formed is

(a) Real, inverted and same in size

(b) Real, inverted and smaller

(c) Virtual, erect and larger

(d) Virtual, erect and smaller

A light beam is being reflected by using two mirrors, as in a periscope used in submarines. If one of the mirrors rotates by an angle q, the reflected light will deviate from its original path by the angle

(a) 2θ

(b) 0°

(c)  θ

(d) 4θ

An ammeter and a voltmeter of resistance R are connected in series to an electric cell of negligible internal resistance. Their readings are A and V respectively.  If another resistance R is connected in parallel with the voltmeter

(a) Both A and V will increase   

(b) Both A and V will decrease 

(c) A will decrease and V will increase

(d) A will increase and V will decrease