# 12th Physics Unit 19 Dawn Of Modren Physics Past Papers MCQs

12th Physics unit 19 Dawn of modern Physics Past papers MCQs. While MCQs are collected from Inter Boards of Lahore. Similarly MCQs from Punjab Boards.

## 12th Physics Unit 19 MCQs

### 2nd Year Physics Unit Dawn of Modern Physics:

Wave nature of light appears in:
(A) Pair production
(B) Compton effect
(C) Photo electric
(D) Interference

The value of Stefan’s constant is: (SWI. GI, 2017)
(A) 2.9×10-‘mk
(B) 1.0974×10’m-
(C) 6.63×10-34]
D 5.67×10-8w-mk4

The Compton shift is equal to Compton wavelength at (DGK. GI, 2017)
(B) 120°
(C) 45°

Which is the most refined form of matter? (DGK. GI, 2015)
(A) Smoke
(B) Fog
(C) Light
(D) Electron

If a particle of mass “m” is moving with speed “y” then de-Broglie wavelength 2 associated
with it will be: (BWP. GI, 2017)
(A) 1 =>
(Β) λ=:
την
mv
2my

The energy of photon is given by: (BWP. GI, 2017)
(A)
(B) hf
(C) ve
(D) m.ca

The principle regarding the dual nature of light was first discovered by: (BWP. GI, 2015)
(A) Compton
(B) J.J Thomson
(C) De-Broglie
(D) Heisenberg

Application of wave like nature of particle is: (GRW.GI, 2015) (MLN. 2018)
(A) Photodiode
(B) Optical microscope
C) Electron microscope
(D) Compound microscope

Pair production can take place only when the energy of radiation is equal and greater than 1.02
MeV, thus correct option is: (BWP. GI, 2017)
(A) X-rays
C) Y-rays
(D) Ultraviolet rays

#### Dawn of Modern Physics 2nd Year Physics MCQs:

Inertial frame is a frame in which: (DGK. GI, 2015)
(A) ist law holds
(B) 2nd law holds
C 3rd law hold
(D) Kelvin’s law holds

The wavelength associated with the proton moving at a speed of 40 m/s is: (LHR. GI, 2018)
(A) 7.20 nm
(B) 9.02 nm
(C) 15.7 nm
(D) 17.3 nm

The energy of the photon of wavelength 500 nm is: (LHR. GI, 2018)
A) 3.10 eV
(B) 2.49 eV
(C) 1.77 eV
(D) 1.52 eV

1. The photon with energy greater than 1.02 MeV can interact with matter as: (LHR. GII, 2018)
(A) Photoelectric effect
(B) Compton effect
C) Pair production
(D) Annihilation of matter

By modern system of NAVSTAR, the speed anywhere on the earth can be determined to
(A) 20 ms
(B) 10 ms-
(C) 2 cms-
(D) 2 ms-!

Which one is low energy photon? (FBD. 2018)
(A) Visible light
B) Infrared light
(C) Ultra violet light
(D) X-rays

The unit of Plank’s constant is: (FBD. 2018)
(A) Joule
B Joule-s
(C) Watt
(D) Candela

Platinum wire becomes yellow at a temperature of: (SWL 2018)
(A) 1100 K
(B) 1300 K
(C) 1573 K
(D) 1873 K

When the speed of the object is half of the speed of light, then (SGD. GII, 2018)
(B) = 27
(A) 1=
(C) –