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
MDCAT Physics Chapter 12 Atomic spectra Induction Online Test MCQs With Answers
Question # 1
For X-rays which of the following is not correct:
Choose an answer
Cause of ionization in air when they pass through it
Can be deflected by electric and magnetic fields
Can be used to detect flaws in metal casting
Travel with the speed of light
Previous
Skip
Next
Question # 2
If an electron is accelerated such that its K.E is 4 times of its rest mass energythen thetotal relativistic energy of electrons is about
Choose an answer
5 × 10–12 J
4 × 10–13 J
3 × 10–13 J
6 × 10–12 J
Previous
Skip
Next
Question # 3
Light elements do not emit X-rays because
Choose an answer
Electrons in it have high binding energy
These materials are non- material
There is a small difference in their energy shells
Electrons in it require very large energy to remove from these materials
Previous
Skip
Next
Question # 4
As the intensity of incident light increases:
Choose an answer
Photoelectric current increases
Photoelectric current decreases
Kinetic energy of emitted photoelectrons increases
Kinetic energy of emitted photoelectrons decreases
Previous
Skip
Next
Question # 5
The potential difference applied to an X-rays tube is increased. As a result, in the emitted radiation
Choose an answer
The intensity increases
The minimum wavelength decrease
The intensity remains unchanged
Both B & C
Previous
Skip
Next
Question # 6
What will be the number of photons emitted per second by 25 W source of monochromatic light of wavelength 600 nm:
Choose an answer
7.5 × 1017
7.5 × 1019
5.5 × 1019
5.5 × 1017
Previous
Skip
Next
Question # 7
The de-Broglie wavelength of the particle of mass m and energy E is:
Choose an answer
ℎ
𝜆 = ℎ√2𝑚𝐸
𝜆 =
1
Previous
Skip
Next
Question # 8
The shortest wavelength of X-rays emitted from an X-rays tube depends on the:
Choose an answer
Current in the tube
Voltage applied to the tube
Nature of gas in the tube
Nature of material of tube
Previous
Skip
Next
Question # 9
A proton, accelerated through a p.d V has a certain de Broglie wavelength. In order to have the same de Broglie wavelength, an 𝑎 −particles must be accelerated through a potential difference:
Choose an answer
4V
8V
V/4
V/8
Previous
Skip
Next
Question # 10
Light of frequency 4f0 is incident on the metal of the threshold frequency f0. The maximum kinetic energy of the emitted photoelectrons is
Choose an answer
3h f0
3/2h f0
2h f0
1/2h f0
Previous
Skip
Next
Question # 11
Ultraviolet radiation of 6.2 eV falls on an aluminium surface having work function ∅ = 𝟒. 𝟐 𝒆𝑽.
The kinetic energy of the fastest electron emitted is:
Choose an answer
4 eV
2 eV
2.2 eV
1.2 eV
Previous
Skip
Next
Back