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# 11. DUAL NATURE OF MATTER AND RADIATION( Objective Question Answer 2022 )

1. De-Broglie equation states the :

(A) dual nature
(B) particle nature
(C) wave nature
(D) none of these

2. Protons and alpha particles have the same de-Broglie wavelength. What is same for both of them ?

(A) Energy
(B) Time period
(C) Frequency
(D) Momentum

3. Kinetic energy of emitted electrons depends upon :

(A) frequency
(B) intensity
(C) nature of atmosphere surrounding the electrons
(D) none of these

4. De-Broglie wavelength of a body of mass m and kinetic energy E is given by (symbols have their usual meanings) :

5. The ratio of specific charge of an alpha particle to the proton is :

(A) 1:2
(B) 2:1
(C) 4:1
(D) 1:4

6. In photo electric emission, for alkali metals the threshold frequency lies in the :

(A) visible region
(B) ultraviolet region
(C) infrared region
(D) far end of the infrared region

7. Which of the following radiations cannot eject photo electrons ?

(A) ultraviolet
(B) infrared
(C) visible
(D) X-rays

8. What is the de-Broglie wavelength of an electron accelerated from rest through a potential difference of 100 volts ?

(A) 12.3 Å
(B) 1.23 Å
(C) 0.123 Å
(D) none of these

9. What is the de-Broglie wavelength of an electron accelerated from rest through a potential difference of V volts ?

10. What is the de-Broglie wavelength of a proton accelerated from rest through a potential difference of V volts ?

11. When a yellow light is incident on a surface, no electrons are emitted while green light can emit electrons. If the red light is incident on the surface then :

(A) no electrons are emitted
(B) photons are emitted
(C) electrons of higher energy are emitted
(D) electrons of lower energy are emitted

12. A metal surface ejects electrons when hit by green light but none when hit by yellow light. The electrons will be ejected when the surface is hit by :

(A) blue light
(B) heat rays
(C) infra-red light
(D) red light

13. Photoelectric effect can be caused by :

(A) X-rays
(B) Visible light
(C) ϒ-rays
(D) All of these