Compared to liquids and solids, gases are:
1.good conductors of electricity
2.best conductors of electricity
3.very poor conductors of electricity
4.good or bad conductors of electricity depending upon the nature of the gas
De-Broglie equation states the:
1.dual nature
2.particle nature
3.wave nature
4.None of the these
Evidence of the wave nature of light cannot be obtained from:
1.diffraction
2.interference
3.doppler effect
4.reflection
In photo electric emission, for alkali metals the threshold frequency lies in the:
1.visible region
2.ultraviolet region
3. infrared region
4.far end of the infrared region
In Thomson’s experiment number of parabola gives :
1.the no. of electrons present in element
2.the no. of proton present in element
3.the no. of neutrons present in element
4. the no. of isotopes of the element present
Kinetic energy of emitted electrons depends upon :
1. frequency
2.intensity
3.nature of atmosphere surrounding the electrons
4.None of the above
Millikan’s oil drop experiment makes use of:
1.Stokes’ law
2.Boyle’s law
3.Gas equation
4.Bernoulli’s theorem
Name the scientists who first studied the passage of electricity through fluids to establish the electrical nature of matter:
1.Millikan
2.Planck
3.Faraday
4.Boyle
Protons and alpha particles have the same de-Broglie wavelength. What is same for both of them ?
1.Energy
2.Time period
3.Frequency
4.Momentum
The de-Broglie wavelength of particle of mass 1 mg moving with a velocity of 1 ms-1, in terms of Planck’s constant h, is given by (in metre):
1.105 h
2.106 h
3.10-3 h
4.103 h
The different stages of discharge in a discharge tube can be explained on the basis of:
1. the wave nature of light
2. the dual nature of light
3. wave nature of electrons
4.the collision between the charged particles emitted from the cathode the atoms of the gas in the tube
The momentum of an electron that emits a wavelength of 2 Ã…. will be:
1.6.4 × 10-36 kgms-1
2.3.3 × 10-24 kgms-1
3.3.3 × 10-34 kgms-1
4.none of these
The ratio of specific charge of an alpha particle to the proton is:
1.1 : 2
2.2 : 1
3.4 : 1
4.1 : 4
The strength of photoelectric current depends upon :
1.angle of incident radiation
2.frequency of incident radiation
3.intensity of incident radiation
4.distance between anode and cathode
The work function of photoelectric material is 3.3 eV. The threshold frequency will be equal to:
1.8 × 1014 Hz
2.8 × 1010 Hz
3.5 × 1010 Hz
4.4 × 1014 Hz
What is the de-Broglie wavelength of an electron accelerated from rest through a potential difference of 100 volts?
1.12.3 Ã…
2.1.23 Ã…
3.0.123 Ã…
4.None of the these
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:
1.no electrons are emitted
2.photons are emitted
3.electrons of higher energy are emitted
4.electrons of lower energy are emitted
which Characteristic of a target does the Mosley’s law relate the frequency of X-rays?
1.density
2.atomic number
3.atomic weight
4.interatomic space
Which of the following radiations cannot eject photo electrons?
1.ultraviolet
2.infrared
3.visible
4.X-rays
X-rays are:
1.deflected by an electric field
2.deflected by a magnetic field
3.deflected by both electric and magnetic fields
4.not deflected by electric and magnetic fields