0.001 kg mass will be equivalent to
1.2.50 GWh
2.25.00 GWh
3.0.26 GWh
4.250 GWh
Posted Date:-2021-08-27 05:10:40
A 10? electric heater is connected to a 220V 50Hz mains supply. What is the peak value of the potential difference across the heater element?
1.220V
2.220/ ??2V
3.110V
4.220 ??2V
Posted Date:-2021-08-27 05:10:40
A choke is used as a resistance in
1.DC circuit
2.AC circuits
3.Both AC and DC circuit
4.Full wave rectifier circuit
Posted Date:-2021-08-27 05:10:40
A device based on photoelectric effect is called
1.photo sensitive detection
2.photo diode
3.photosynthesis
4.photo cell
Posted Date:-2021-08-27 05:10:40
A photon is
1.a unit of energy
2.a positively charged particle
3.a quantum of electromagnetic radiation
4.a unit of wavelength
Posted Date:-2021-08-27 05:10:40
A photon of wave length 900nm behaves like a particle of mass
1.5.53 x 10-36kg
2.0 kg.
3.2.46 x 10-36kg
4.1.84 x 10-44kg
Posted Date:-2021-08-27 05:10:40
A three dimensional image is obtained by
1.Electron microscope
2.Seanning electron microscope
3.Magnetic imaging
4.None of the above
Posted Date:-2021-08-27 05:10:40
a voltage V = V? cos ?t is applied across a resistor of resistance R the average power dissipated per cycle in the resistor is given by
1.V?/?2R
2.V?/?2?R
3.V?2/?2R
4.V?2/?2?R
Posted Date:-2021-08-27 05:10:40
After traveling through a vacuum a photon of light entering into some transparent denser medium. Thus the energy of light
1.Increases because wavelength decreases
2.Decreases because speed decreases
3.Remains same
4.Increases then decreases
Posted Date:-2021-08-27 05:10:40
An A.C series circuit containing 4? resistance and 3-? inductive reactance. The impedance of the circuit is
1.1?
2.5?
3.7?
4.7/?2?
Posted Date:-2021-08-27 05:10:40
An alternating potential difference is connected across a pure resistor and the frequency of the supply is varied but the rms value of the voltage is kept constant. The mean rate of heat dissipated from the resistor is
1.Directly proportional to f
2.Directly proportional to ??f
3.Directly proportional to f2
4.Inversely proportional to f
Posted Date:-2021-08-27 05:10:40
An inductive coil has a resistance of 100?. When an AC signal of frequency 1000Hz is fed to the coil the applied voltage leads the current by 45?. What is the inductance of the coil?
1.10mH
2.12mH
3.16mH
4.20mH
Posted Date:-2021-08-27 05:10:40
An inductor may store energy in
1.its electric field
2.its coils
3.its magnetic field
4.both electric and magnetic fields
Posted Date:-2021-08-27 05:10:40
An observer shoots parallel to a meter stick at very high (relativistic) speed and finds that the length of meter stick is
1.greater than one meter
2.less than one meter
3.one meter
4.a foolish question
Posted Date:-2021-08-27 05:10:40
As the temperature of black body is raised the wavelength corresponding to maximum intensity
1.shifts towards longer wavelength
2.shifts towards shorter wavelength
3.remain the same
4.shifts towards longer as well as shorter wavelengths
Posted Date:-2021-08-27 05:10:40
At resonance the value of the power factor in an L-C-R series circuit is
1.Zero
2.2
3.1
4.not definite
Posted Date:-2021-08-27 05:10:40
Choose the correct statement. In the case of AC circuit ohms law holds for
1.Peak values of voltage and current
2.Effective values of voltage and current
3.Instantaneous values of voltage and current
4.All of the above
Posted Date:-2021-08-27 05:10:40
Compton effect proves the
1.Photon theory of light
2.Dual nature of light
3.Wave nature of light
4.Uncertain nature of light
Posted Date:-2021-08-27 05:10:40
Davison Germer experiment indicates
1.interference
2.polarization
3.election diffraction
4.refraction
Posted Date:-2021-08-27 05:10:40
Einsteins photoelectric equation is given by
1.1/2 mvmax2=hf+?
2.1/2 mvmax2-hf = ?
3.1/2 mvmax2=hf-?
4.all of above are correct
Posted Date:-2021-08-27 05:10:40
For confinement of electron in a box of radius 10-14m the electron speed should be
1.107m/sec
2.Should be greater than speed of light.
3.Be zero
4.Not be wavelike.
Posted Date:-2021-08-27 05:10:40
If a diffraction grating is placed in the path of a light beam it reveals
1.Wave property
2.Particle property
3.Energy particle
4.Electromagnetic wave property
Posted Date:-2021-08-27 05:10:40
If a material object moves with speed of light its mass becomes
1.equal to its rest mass
2.double of its rest mass
3.infinite
4.zero
Posted Date:-2021-08-27 05:10:40
If the wavelength of incident radiation is increased in photoemission then
1.The maximum kinetic energy of the photoelectrons increases.
2.The minimum kinetic energy of the photoelectrons decreases.
3.The minimum kinetic energy of the photoelectrons increases.
4.The average kinetic energy of the photoelectrons decreases.
Posted Date:-2021-08-27 05:10:40
In a photoelectric effect monochromatic light is incident on a metal surface. If the incident light of twice the intensity but of same wavelength the kinetic energy of the emitted electron
1.Becomes double
2.Remains same
3.Becomes half
4.First increases then decreases because curvilinear graph
Posted Date:-2021-08-27 05:10:40
In an LCR series circuit, if V is the effective value of the applied voltage VR is the voltage across R VL is the effective voltage across L & Vc is the effective voltage across C then
1.V = VR+VL+VC
2.V2 = VR2+VL2+VC2
3.V2 = VR2+(VL-VC)2
4.V2 = VL2+(VR-VC)2
Posted Date:-2021-08-27 05:10:40
In Compton scattering the change in wave length is max if
1.angle of scattering is 90?
2.angle of scattering is 60?
3.angle of scattering is 180?
4.angle of scattering is zero
Posted Date:-2021-08-27 05:10:40
In Davisson-Germer experiment the diffracted proton from crystal shows
1.Particle property
2.Wave property
3.Light property
4.Quantum property
Posted Date:-2021-08-27 05:10:40
In electron microscope electric & magnetic fields are used as
1.Electromagnetic gun.
2.Source of electromagnetic waves.
3.Deflecting charged particle
4.Converging source of electrons.
Posted Date:-2021-08-27 05:10:40
In electron microscope we use energetic particles because of
1.Penetrating power is high
2.Kinetic energy is large.
3.Wavelength is very short.
4.All the above reasons.
Posted Date:-2021-08-27 05:10:40
Linear momentum of a photon is
1.zero
2.hv/c2
3.hv/c
4.c2/hv
Posted Date:-2021-08-27 05:10:40
Mark the wrong statement.
1.a frame of reference which is either at rest or moves with a constant velocity is called an inertial frame of reference
2.an un-accelerated frame of reference is called an inertial frame of reference
3.all the frames of reference in uniform rectilinear motion are equivalent
4.Newtons laws of motion are valid in an accelerated (non inertial) frame of reference
Posted Date:-2021-08-27 05:10:40
Rest mass of a photon is
1.infinite
2.zero
3.very small
4.1.67 x 10-27 kg
Posted Date:-2021-08-27 05:10:40
Select an alternative from of uncertainly principle from the following
1.?? = h/m?c(1-cos ?)
2.?E . ?t = h
3.mc2 = hv
4.any of above
Posted Date:-2021-08-27 05:10:40
Stopping potential for a metal surface in case of photoelectric emission depends on
1.the threshold frequency for the metal surface
2.the intensity of incident light
3.the frequency of incident light and work function of the metal surface
4.all of the above
Posted Date:-2021-08-27 05:10:40
The energy radiated is directly proportional to fourth power of Kelvins temperature is
1.Karl-weins law
2.Rayleigh Jeans law.
3.Stephens law.
4.Plancks
Posted Date:-2021-08-27 05:10:40
The existence of Ether wind was experimentally rejected by
1.equal to its rest mass
2.double of its rest mass
3.infinite
4.zero
Posted Date:-2021-08-27 05:10:40
The frequency of a circuit consisting of a capacitance C and a resistor R is
1.C/R
2.R/C
3.1/RC
4.1/ ??RC
Posted Date:-2021-08-27 05:10:40
The linear momentum of an X-ray photon of wavelength 0.1A is
1.6.625x1023N-s
2.66.25x1023N-s
3.662.5x1023N-s
4.data is insufficient
Posted Date:-2021-08-27 05:10:40
The name of the photon for quantum of light was proposed by
1.Ampere
2.Plank
3.Thomson
4.Einstein
Posted Date:-2021-08-27 05:10:40
The phase angle between the voltage and the current in an AC circuit consisting of a resistance is
1.Zero
2.45?
3.90?
4.180?
Posted Date:-2021-08-27 05:10:40
The relativistic energy E is equivalent to relativistic mass given by
1.Ec2
2.E/c2
3.E/c
4.c2/E
Posted Date:-2021-08-27 05:10:40
The uncertainty in momentum & position is due to its
1.Property of matter and radiation.
2.Two dimensional motion.
3.Emission of certain wavelength
4.Very high velocity.
Posted Date:-2021-08-27 05:10:40
Tick the correct statement
1.the flight path of a vertically falling body appears straight to the stationary observer
2.the flight path of vertically falling body appears parabolic to an observer in uniform relative motion
3.all states of rest and motion are relative and there is no such thing as absolute motion
4.all the above
Posted Date:-2021-08-27 05:10:40
Tick the right statement.
1.no photo electronic emission takes place if the frequency of radiation however intense it may be is less than a certain critical value called threshold frequency
2.threshold frequency depends upon the nature of the metal surface
3.maximum energy of a photoelectron is a function of frequency rather than intensity of radiation
4.all of the above
Posted Date:-2021-08-27 05:10:40
Two identical coaxial circular loops carry equal currents in the same direction. If the loops approach each other the current in
1.Each increases
2.Each decreases
3.Each remains the same
4.One increases whereas that in the other decreases
Posted Date:-2021-08-27 05:10:40
What is the self inductance of a coil in which an induced emf of 2V is set up when the current changes at the rate of 4 As-1?
1.0.5 mH
2.0.5H
3.2.0H
4.8.0H
Posted Date:-2021-08-27 05:10:40
When a pure inductor of inductance L and a pure capacitor of capacitance C are connected in parallel to a sinusoidal potential difference V the potential difference across both L & C will be
1.Same
2.Different
3.At L will be more than at C
4.At L will be less than at C
Posted Date:-2021-08-27 05:10:40
Which one of the following has the largest energy content?
1.103 photons of wavelength 2pm (?-rays).
2.102 photons of wavelength 1nm (x-rays).
3.106 photons of wavelength 50?m (infrared).
4.106 photons of wavelength 200nm (UV).
Posted Date:-2021-08-27 05:10:40
Which one of the following radiations has the strongest photon?
1.T.V waves
2.micro waves
3.X-rays
4.?-rays
Posted Date:-2021-08-27 05:10:40