0.001 kg mass will be equivalent to
1.2.50 GWh
2.25.00 GWh
3.0.26 GWh
4.250 GWh
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
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
A device based on photoelectric effect is called
1.photo sensitive detection
2.photo diode
3.photosynthesis
4.photo cell
A photon is
1.a unit of energy
2.a positively charged particle
3.a quantum of electromagnetic radiation
4.a unit of wavelength
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
A three dimensional image is obtained by
1.Electron microscope
2.Seanning electron microscope
3.Magnetic imaging
4.None of the above
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
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
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?
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
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
An inductor may store energy in
1.its electric field
2.its coils
3.its magnetic field
4.both electric and magnetic fields
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
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
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
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
Compton effect proves the
1.Photon theory of light
2.Dual nature of light
3.Wave nature of light
4.Uncertain nature of light
Davison Germer experiment indicates
1.interference
2.polarization
3.election diffraction
4.refraction
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
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.
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
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
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.
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
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
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
In Davisson-Germer experiment the diffracted proton from crystal shows
1.Particle property
2.Wave property
3.Light property
4.Quantum property
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.
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.
Linear momentum of a photon is
1.zero
2.hv/c2
3.hv/c
4.c2/hv
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
Rest mass of a photon is
1.infinite
2.zero
3.very small
4.1.67 x 10-27 kg
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
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
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
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
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
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
The name of the photon for quantum of light was proposed by
1.Ampere
2.Plank
3.Thomson
4.Einstein
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?
The relativistic energy E is equivalent to relativistic mass given by
1.Ec2
2.E/c2
3.E/c
4.c2/E
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.
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
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
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
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
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
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).
Which one of the following radiations has the strongest photon?
1.T.V waves
2.micro waves
3.X-rays
4.?-rays