More Classes
5th Class
6th Class
7th Class
8th Class
9th Class
10th Class
11th Class
12th Class
NAT I
NAT II
CSS
IQ
General Knowledge
MDCAT
ECAT
GAT General
GAT Subject
Other Links
Go to Home
Online Tests
ECAT Physics Chapter 19 Dawn of Modern Physics Online Test MCQs With Answers
Question # 1
The special theory of relativity treats problems invoving
Choose an answer
inertial frame of references
accelerating frame of references
both of these
none of these
Previous
Skip
Next
Question # 2
When a platinum wire is heated, it appears white at
Choose an answer
1600
°C
900
°C
1100
°C
1300
°C
Previous
Skip
Next
Question # 3
When a platinum wire is heated, it appears dull red at about
Choose an answer
500°C
900°C
1100°C
1300°C
Previous
Skip
Next
Question # 4
At the temperature, a body emits radiation which is principally
Choose an answer
of long wavelengths in the visible region
of long wavelengths in the invisible infrared region
of short wavelength in invisible ultraviolet region
none of these
Previous
Skip
Next
Question # 5
When a high energy photon interact with a metal, which of the following effect is most likely to be taken place
Choose an answer
pair production
photoelectric effect
Compton effect
None of these
Previous
Skip
Next
Question # 6
When a platinum wire is heated, it appears orange red at
Choose an answer
500
°C
900
°C
1100
°C
1300
°C
Previous
Skip
Next
Question # 7
From the theory of relativity, momentum p of the photon is related to energy as
Choose an answer
p = hfc
p = hf/c
p = f(hc,f)
p = cf/h
Previous
Skip
Next
Question # 8
The Nobel Prize on the explanation of photoelectric effect was awarded to:
Choose an answer
Max. Planck
Maxwell
Bohr
Rutherford
None of these
Previous
Skip
Next
Question # 9
The whole shape of the black body spectrum for all wavelengths was explained by the formula proposed by
Choose an answer
Max plank
Newton
Einstein
J.J. Thomson
Previous
Skip
Next
Question # 10
Intensity of light determines the:
Choose an answer
Energy of each photon
Number of photons
Speed of photons
Size of photons
None of these
Previous
Skip
Next
Question # 11
When low energy photon interact with a metal,which of the following effect is likely to be taken place
Choose an answer
pair production
photoelectric
Compton effect
None of these
Previous
Skip
Next
Question # 12
S.I. unit of planks constant is
Choose an answer
J-s
-1
J.s
J.s
-2
J.s
2
Previous
Skip
Next
Question # 13
According to the Max plank, energy is redialed or absorbed in
Choose an answer
discrete packets
continuous waves
either of them
none of these
Previous
Skip
Next
Question # 14
When a position comes close to an electron they annihilate into
Choose an answer
one photon
two photons which travel in the same direction
two photons which travels in the opposite direction
two photons which travel in any direction
Previous
Skip
Next
Question # 15
Practically the quantity v/c is always:
Choose an answer
less than one
Equal to one
Greater then one
all of these
None of these
Previous
Skip
Next
Question # 16
When platinum wire is heated, it appears cherry red at
Choose an answer
1600
°C
900
°C
1100
°C
1300
°C
Previous
Skip
Next
Back