MCAT MCQ Quiz Hub

1. 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
Same
Different
At L will be more than at C
At L will be less than at C

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
Directly proportional to f
Directly proportional to ??f
Directly proportional to f2
Inversely proportional to f

3. 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?
0.5 mH
0.5H
2.0H
8.0H

4. The frequency of a circuit consisting of a capacitance C and a resistor R is
C/R
R/C
1/RC
1/ ??RC

5. 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?
220V
220/ ??2V
110V
220 ??2V

6. A choke is used as a resistance in
DC circuit
AC circuits
Both AC and DC circuit
Full wave rectifier circuit

7. At resonance the value of the power factor in an L-C-R series circuit is
Zero
2
1
not definite

8. An A.C series circuit containing 4? resistance and 3-? inductive reactance. The impedance of the circuit is
1?
5?
7?
7/?2?

9. 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?
10mH
12mH
16mH
20mH

10. Choose the correct statement. In the case of AC circuit ohms law holds for
Peak values of voltage and current
Effective values of voltage and current
Instantaneous values of voltage and current
All of the above

11. The phase angle between the voltage and the current in an AC circuit consisting of a resistance is
Zero
45?
90?
180?

12. 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
V = VR+VL+VC
V2 = VR2+VL2+VC2
V2 = VR2+(VL-VC)2
V2 = VL2+(VR-VC)2

13. 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
V?/?2R
V?/?2?R
V?2/?2R
V?2/?2?R

14. Two identical coaxial circular loops carry equal currents in the same direction. If the loops approach each other the current in
Each increases
Each decreases
Each remains the same
One increases whereas that in the other decreases

15. An inductor may store energy in
its electric field
its coils
its magnetic field
both electric and magnetic fields

16. Tick the correct statement
the flight path of a vertically falling body appears straight to the stationary observer
the flight path of vertically falling body appears parabolic to an observer in uniform relative motion
all states of rest and motion are relative and there is no such thing as absolute motion
all the above

17. Mark the wrong statement.
a frame of reference which is either at rest or moves with a constant velocity is called an inertial frame of reference
an un-accelerated frame of reference is called an inertial frame of reference
all the frames of reference in uniform rectilinear motion are equivalent
Newtons laws of motion are valid in an accelerated (non inertial) frame of reference

18. The relativistic energy E is equivalent to relativistic mass given by
Ec2
E/c2
E/c
c2/E

19. An observer shoots parallel to a meter stick at very high (relativistic) speed and finds that the length of meter stick is
greater than one meter
less than one meter
one meter
a foolish question

20. 0.001 kg mass will be equivalent to
2.50 GWh
25.00 GWh
0.26 GWh
250 GWh

21. Which one of the following radiations has the strongest photon?
T.V waves
micro waves
X-rays
?-rays

22. Tick the right statement.
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
threshold frequency depends upon the nature of the metal surface
maximum energy of a photoelectron is a function of frequency rather than intensity of radiation
all of the above

23. Linear momentum of a photon is
zero
hv/c2
hv/c
c2/hv

24. A device based on photoelectric effect is called
photo sensitive detection
photo diode
photosynthesis
photo cell

25. The linear momentum of an X-ray photon of wavelength 0.1A is
6.625x1023N-s
66.25x1023N-s
662.5x1023N-s
data is insufficient

26. Stopping potential for a metal surface in case of photoelectric emission depends on
the threshold frequency for the metal surface
the intensity of incident light
the frequency of incident light and work function of the metal surface
all of the above

27. Select an alternative from of uncertainly principle from the following
?? = h/m?c(1-cos ?)
?E . ?t = h
mc2 = hv
any of above

28. The existence of Ether wind was experimentally rejected by
equal to its rest mass
double of its rest mass
infinite
zero

29. If a material object moves with speed of light its mass becomes
equal to its rest mass
double of its rest mass
infinite
zero

30. As the temperature of black body is raised the wavelength corresponding to maximum intensity
shifts towards longer wavelength
shifts towards shorter wavelength
remain the same
shifts towards longer as well as shorter wavelengths

31. Rest mass of a photon is
infinite
zero
very small
1.67 x 10-27 kg

32. The name of the photon for quantum of light was proposed by
Ampere
Plank
Thomson
Einstein

33. Einsteins photoelectric equation is given by
1/2 mvmax2=hf+?
1/2 mvmax2-hf = ?
1/2 mvmax2=hf-?
all of above are correct

34. In Compton scattering the change in wave length is max if
angle of scattering is 90?
angle of scattering is 60?
angle of scattering is 180?
angle of scattering is zero

35. Davison Germer experiment indicates
interference
polarization
election diffraction
refraction

36. A photon is
a unit of energy
a positively charged particle
a quantum of electromagnetic radiation
a unit of wavelength

37. Which one of the following has the largest energy content?
103 photons of wavelength 2pm (?-rays).
102 photons of wavelength 1nm (x-rays).
106 photons of wavelength 50?m (infrared).
106 photons of wavelength 200nm (UV).

38. After traveling through a vacuum a photon of light entering into some transparent denser medium. Thus the energy of light
Increases because wavelength decreases
Decreases because speed decreases
Remains same
Increases then decreases

39. 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
Becomes double
Remains same
Becomes half
First increases then decreases because curvilinear graph

40. If the wavelength of incident radiation is increased in photoemission then
The maximum kinetic energy of the photoelectrons increases.
The minimum kinetic energy of the photoelectrons decreases.
The minimum kinetic energy of the photoelectrons increases.
The average kinetic energy of the photoelectrons decreases.

41. A photon of wave length 900nm behaves like a particle of mass
5.53 x 10-36kg
0 kg.
2.46 x 10-36kg
1.84 x 10-44kg

42. In Davisson-Germer experiment the diffracted proton from crystal shows
Particle property
Wave property
Light property
Quantum property

43. If a diffraction grating is placed in the path of a light beam it reveals
Wave property
Particle property
Energy particle
Electromagnetic wave property

44. In electron microscope we use energetic particles because of
Penetrating power is high
Kinetic energy is large.
Wavelength is very short.
All the above reasons.

45. In electron microscope electric & magnetic fields are used as
Electromagnetic gun.
Source of electromagnetic waves.
Deflecting charged particle
Converging source of electrons.

46. A three dimensional image is obtained by
Electron microscope
Seanning electron microscope
Magnetic imaging
None of the above

47. The uncertainty in momentum & position is due to its
Property of matter and radiation.
Two dimensional motion.
Emission of certain wavelength
Very high velocity.

48. For confinement of electron in a box of radius 10-14m the electron speed should be
107m/sec
Should be greater than speed of light.
Be zero
Not be wavelike.

49. The energy radiated is directly proportional to fourth power of Kelvins temperature is
Karl-weins law
Rayleigh Jeans law.
Stephens law.
Plancks

50. Compton effect proves the
Photon theory of light
Dual nature of light
Wave nature of light
Uncertain nature of light