| 1 |
As the current flows through the wire |
It generates heat in the wire
It produces sound in the wire
Resistance of the wire decrease
Voltage across the ends is the increase
None of these
|
| 2 |
The minimum wavelength of X-rays produced of 1KV potential difference is applied across the anode and cathode of the tube is |
1.24 x 10<sup>-10</sup>m
7.92 x 10<sup>-20</sup>m
2.78 x 10<sup>-14</sup>m
3.88 x 10<sup>-11</sup>m
|
| 3 |
CT scanning is the abbreviated name of |
Computed Technology
Computed Technique
Computed Technology
Computerized Technique
|
| 4 |
The first shell near the neucles is |
L-shell
X-shell
N-shell
M-shell
|
| 5 |
The fourth band is a: |
Silver band
Red band
Gold band
Either A or C
Either A or B
|
| 6 |
The life time of metastable state is equal to |
Life time of excited state
Greater than by excited state
Zero
Less than by excited state
|
| 7 |
We can excite an atom by |
Bombardment of particles
Radiating photons
Providing potential difference
All answer are true
|
| 8 |
The value of resistivity is the least for: |
Copper
Aluminimum
Silver
Tungsten
Iron
|
| 9 |
In a metal, the valence electrons are: |
Attached to individual atoms
Not attached to individual atoms
Free to move within the metal
Both A and B
Both A and C
|
| 10 |
Ultraviolet region lies in ______ series |
Layman
Balmer
P fund
B racket
|
| 11 |
In gases, the charge carriers are: |
Electrons
Positive ions
Negative ions
Both A and C
Both A and B
|
| 12 |
Graph of Black body radiation is example of |
Band spectra
Continuo's spectra
Line spectra
All
|
| 13 |
Photons must have energy equal to |
ev
En
hf
None of these
|
| 14 |
In order to get interference using two light rays |
The sources should be monochromatic and coherent
The sources should have the same frequency
Superposition should be linear
All of these
|
| 15 |
The superposition of the two waves of same frequency and amplitude travelling in the same direction gives to an effect called |
Diffraction
Interference
Polarization
Dispersion
|
| 16 |
The locus of all points in a medium having same phase of vibration is called |
Crest
Trough
Wavelength
Wave-front
|
| 17 |
Gaussian surface is always: |
Rectangular
Spherical
Cylinder
Box shape
Any of these
|
| 18 |
According to Huygen's principle |
light travels in straight line
Light is a transvers wave
Light has dual nature
All points on the primary wave-front are the sources of secondary wavelets
|
| 19 |
The cause of mirage observed in deserts in bright sunlight is due to |
Refraction of light
Reflection of light
Scattering of light
Total internal reflection of light
|
| 20 |
Coulomb multiplied by volt by volt gives the unit called: |
farad
Ohm
Second
joule
Watt
|
| 21 |
The velocity of light in vacuum can be changed by changing |
Frequency
Amplitude
Wavelength
None of these
|
| 22 |
The image of the tip of a needle is never sharp because of |
Polarization of light
Interference of light
Diffraction of light
Reflection of light
|
| 23 |
Which one the following gives three regions of electromagnetic spectrum in order of increasing wavelength? |
Gamma rays, micro waves, visible light
Radio waves, ultraviolet waves, X-rays
Ultraviolet rays, infrared rays, micro waves
Visible light, gamma rays, radio waves
|
| 24 |
Huygen's theory cannot explain |
Diffraction
Interference
Polarization
Photoelectric effect
|
| 25 |
The contrast in the fringes in an interference pattern depends upon |
Fringe width
Relative difference intensities of the two sources
Distance between the slits
Wavelength
|
| 26 |
Static electricity is produced by the transfer of: |
Electrons
Protons
One fluid
Two fluid
None of these
|
| 27 |
If yellow light emitted by sodium lamp in Young's double slit experiment is replaced by blue light of the same intensity |
Fringe width will decrease
Fringe width will increase
Fringe width will remain unchanged
Fringe will become less intense
|
| 28 |
The electric field lines start from: |
Positive charge
Negative charge
Either A and B
Neutron
An atom
|
| 29 |
Which one of the following phenomenon cannot be explained on the bases of Huygen's theory |
Refraction
Reflection
Diffraction
Formation of spectrum
|
| 30 |
The photocopying process is called: |
Geography
Sonography
Xerography
Zerography
None of these
|