MCAT MCQ Quiz Hub

1. Central spot of Newtons rings
bright
dark for large wavelength
dark
bright for large wavelength

2. A point source of light placed in a homogeneous medium gives rise to
a cylindrical wave front
an elliptical wave front
a spherical wave front
a plane wave front

3. The locus of all points in a medium having the same phase of vibration is called
crest
trough
wavelength
wave front

4. Which one of the following is nearly monochromatic light ?
light form fluorescent tube
light form neon lamp
light form sodium lamp
light form simple lamp

5. Two sources of light are coherent if they emit rays of
same wavelength
same amplitude of vibration
same wave length with constant phase difference
same amplitude and wavelength

6. When crest of one wave falls over the trough of the other wave this phenomenon is known as
polarization
constructive interference
destructive interference
diffraction

7. In Youngs double slit experiment the fringe spacing is equal to
d?D
2?d/D
?D/d
?d/D

8. In Young double slit experiment, if white light is used
alternate dark and bright fringes will be seen
coloured fringes will be seen
no interference fringes will be seen
impossible to predict

9. The velocity of light was determined accurately by
Newton
Michelson
Huygen
Young

10. The condition for constructive interference of two coherent beams is that the path difference should be
integral multiple of ?/2
integral multiple of ?
odd integral multiple of ?/2
even integral multiple of ?

11. In an interference pattern
bright fringes are wider than dark fringes
dark fringes are wider than bright fringe
both dark and bright fringes are of equal width
central fringes are brighter than the outer fringes

12. appearance of colour in thin films is due to
diffraction
dispersion
interference
polarization

13. The blue colour of the sky is due to
diffraction
reflection
polarization
scattering

14. A light ray traveling form rarer to denser medium suffers a phase change of
60?
90?
180?
45?

15. When one mirror of a Michelson Interferometer is moved a distance of 0.5 mm we observe 2000 fringes. What will be wavelength of light used?
5000 nm
5000A?
500m
2000um

16. Diffraction effect is
more for a round edge
less for a round edge
more for a sharp edge
less for a sharp edge.

17. The wavelengthe of X-rays is of the order of
10A?
1000 A?
1A?
100 A?

18. Wavelength of X-rays falling at glancing angle of 30? on a crystal with atmic spacing 2 x 10-10 for the fist order diffraction is
4 x 10-10 m
2 x 10-10 m
0.02x10-10m
20x10-10m

19. A diffraction grating has 500 lines per mm. Its slit spacing or grating element will be equal to
500 mm
5 x 10-3 mm
2 x 10-5 mm
2 x 10-3 mm

20. In a plane polarized light
vibration in all direction
vibration in two mutually perpendicular directions
vibration take place in a direction perpendicular to the direction of propagation of light
no vibration at all

21. Light on passing through a Polaroid is
plane polarized
un-polarized
circularly polarized
elliptically polarized

22. Which one of the following cannot be polarized?
radio waves
ultraviolot rays
X-rays
sound waves

23. Diffarction fringes are
equally spaced
distance between them increases
distance between then decreases
they are adjacent with no space in between

24. In monochromatic red light a blue book will probably appear to be
black
purple
green
no scientific reasoning available

25. A thing that emits its own light is
luminous
non-luminous
incandescent
bright

26. In double slit experiment if one of the two slit is covered then
no interference fringes are observed
no diffraction fringes are observed
no fringes observed
interference pattern not disturbed

27. gives the definition of metre in terms of wavelength of red cadmium light
Newton
Einstein
Michelson
Galileo

28. In Michelson interferometer to switch the fringe from bright to dark the mirror should be displaced through
? / 2
?/3
?/6
?/4

29. In the shadow of a ball the central portion appears bright that happens due to
Interference
Diffraction
Polarization
Refraction

30. Which experiment shows that wavelength of light is smaller than that of sound
Diffraction
Polarization
Interference
Reflection

31. Crystals of a material can behave as
Convex lens
Interferometer
Diffraction grating
Concave

32. When we rub a glass rod with a silk cloth then
glass rod acquires negative charge while silk acquires positive charge
glass rod acquires positive charge while silk acquires negative charges
both glass rod and silk acquire negative charge
both glass rod and silk acquire positive charge

33. If the distance between the two point charges become half then force between them becomes
double
half
four times
remains same

34. The minimum charge on any object cannot be less than
1.6 x 10-19C
3.2 x 10-19C
9.1 x 109C
no definite value exist

35. Electric charge of 100 ?C is 13cm apart from another charge 16.9?C electric force between them is
9x107N
900N
9x105N
9x106N

36. Electric force between two point charges in air or vacuum is F. If we replace air or vacuum by an insulator (dielectric) of relative permitivity Cr the force between the charges will
decrease
increase
remain constant
depends upon composition of dielectric

37. Two charges are placed at a certain distance. If the magnitude of each charge is doubled the force will become
1/4th of its original value
1/8th of its original value
4 times of its original value
8 times of its original value

38. The force per unit charge is know as
electric flux
electric intensity
electric potential
all of above are same

39. An electric field can deflect
neutrons
?-rays
both glass rod and silk acquire negative charge
none

40. An electric charge at rest produces
only a magnetic field
only an electric field
neither electric field nor magnetic field
both electric and magnetic fields

41. Tick the only wrong statement.
similar charges repel each other
dissimilar charges attract each other
repulsion is the sure test of electrification
an electrically neutral body is repelled both positively and negatively charged bodies

42. Electric intensity being a vector quantity always points
along the direction of force experienced by a unit positive charge
opposite to the direction of force experienced by a unit positive charge
perpendicular to the direction of force experienced by a uit positive charge
any of above

43. Electric flux linked with a surface will be maximum when
the surface is held parallel to the electric field
the surface is held perpendicular to the electric field
the surface makes an angle of 45?with the field
all of the above

44. A closed surface contains two equal and opposite charges. The net electric flux from the surface will be
negative
positive
zero
data is insufficient

45. The electric lines of force are
imaginary
physically existing every where
physically existing near the charges
depends upon case

46. Tick the correct statement
the electric lines of force have no physical existence
they expand laterally and contract longitudinally
they do not cross each other and group together in dielectric
all the above statements are true

47. If free space between the plates of a capacitor is replaced by a dielectric
The potential difference remains constant capacittance and energy stored increases
The potential difference remains constant capacittance decreases and energy increases
The potential difference decreases but both capacitance and energy increase
both potential difference and capacitance decrease but energy increases

48. Two similar charges each of one coulomb placed in air one meter apart repel each other with a force
9 x 109N
9.2 x 104N
9 x 109N
9 x 107N

49. A hollow metallic sphere of 8cm diameter is charged with 4 x 10 8C. The potential on its surface will be
900 volts
9000 volts
90 volts
zero

50. The metallic spheres A and B of radii 2m and 4m respectively carry the same charge 4 x 10 8C. If the spheres are connected by a copper wire
charge will flow from A to B
charge will flow from B to A
no flow of charge will occur
both a and b are possible