MCAT MCQ Quiz Hub

1. The penetrating power of X-rays is comparable with that of
? - rays
? - rays
? - rays
all of above

2. Quality of X-rays depends upon ___________ A-filament current B-accelerating voltage C-material of the target
A&B
B&C
A&C
A B & C

3. Radiation produced from TV picture tube is
?-rays
X-rays
Far infrared.
Infrared

4. In an X-ray tube electrons each of charge e are accelerated through V potential difference allowed to hit a metal target. The wavelength of the X-rays emitted is
he/ev
he/Vc
eV/h
impossible to predict

5. The minimum wavelength of X-rays can further be reduced by
Reducing the pressure or cooling the target.
Increasing the temperature of the filament.
Using a target element of higher atomic number.
Increasing the potential difference between the cathode and the target.

6. The characteristic X-rays spectrum is due to
The illumination of the target metal by ultra-violet radiation.
The bombardment of the target by protons.
The bombardment of target by electrons.
The absorption of ? radiation by the target metal.

7. The minimum wavelength of X-rays produced by the bombardment of electrons on the screen of a television set where the accelerating potential is 2.0K V will be
6.2 x 10-10m
9.1 x 10-18m
3.11 x 10-10m
4 x 10-10m

8. Maximum frequency in the spectrum from X-ray tube is directly proportional to the
Number of incident electron i.e. filament current.
The kinetic energy of the incident electron i.e. the potential difference through which they are accelerated.
The soft target which can easily emit electrons.
all of above are correct.

9. X-rays are diffracted by a crystal but not by a diffraction grating because
The ions in a crystal are well arranged.
The lines in a diffraction grating cannot reflect X-rays.
The penetration power of X-rays is high in a diffraction grating.
The wavelengths of X-rays are of the same order of magnitude as the separation between atoms in a crystal

10. UV radiation can be produced by
Heating the filament.
Electron excitation in the gas.
Ionization of atoms.
All the above.

11. What is the velocity of a particle of mass m & de-Broglie wavelength ??
h/m?
2h/m?
mh/h
(2hc/m?)1/2

12. Wave-like characteristic of electron is demonstrated by
Line spectrum of atoms.
Production of x-rays.
Diffraction by crystalline solids.
Photoelectric effect.

13. Electron cannot exist in the nucleus it is confirmed by observing that
It does emit ?-radiation.
Its size as compare to proton and neutron is very small.
No antiparticle of electron is present.
The velocity of electron must be very high according to uncertainty principle.

14. In normal state of energy the incident high energy photons will be
Stimulated.
Absorbed.
Cause X-ray emission.
Cause laser production

15. In laser production the state in which more atoms are in the upper state than in the lower one is called
Metal stable state.
Normal state.
Inverted population.
All the above.

16. The metastable state for an atom in laser light is
10-4 sec
10-5 sec
10-3 sec
10-8 sec

17. In He-Ne laser the lasing action is produced by
Ne only.
He-Ne both
Electrons of He.
Electrons Ne.

18. Reflecting mirrors in laser is used to
Further stimulation
Lasing more
For producing more energetic lasers.
All

19. The velocity of laser light is
Less than ordinary light.
More than ordinary light.
Equal to ordinary light.
Different for different colours or frequency.

20. When body is in motion, ________ always changes.
its velocity
its acceleration
its position vector
its momentum

21. A body is moving with uniform velocity. Its
speed changes
acceleration changes
direction of motion changes
displacement from origin changes

22. A man is in a car is moving with velocity of 36km/hr. His speed with repect to the car is
10m/s
36m/s
zero
infinite

23. When velocity time graph is a straight line parallel to time axis then
acceleration is const
acceleration is variable
acceleration is zero
velocity is zero

24. Area under velocity time graph represent
force
displacement
distance
acceleration

25. Slope of velocity time graph is
acceleration
distance
force
momentum

26. Instantaneous and average velocities become equal when body
has zero acceleration
has uniform acceleration
has variable acceleration
moves in a circle

27. Which law of motion is also called law of inertia?
1st law
2nd law
3rd law
all 1st, 2nd and 3rd laws

28. Inertia of an object is quantitative measure of its
volume
density
mass
temperature

29. Newtons laws do not hold good for particles
at rest
moving slowly
move with high velocity
move with velocity comparable to velocity of light

30. 1st law of motion gives the definition of
rest
motion
velocity
force

31. 2nd law of motion gives the definition of
force
acceleration
velocity
both force and acceleration

32. 3rd law of motion explains
effect of force
existence of a force
existence of two forces
existence of pair of forces in nature

33. Momentum depends upon
force acts on the body
mass of the body
velocity of the body
both mass and velocity of the body

34. The dimension of force is
MLT-2
ML2T-2
ML2T2
ML-2T-2

35. When a body moves in a straight line then its displacement coincides with
distance
force
acceleration is zero
both (a) and (b)

36. Which of the following pair has same direction always?
force, displacement
force, velocity
force, acceleration
force, momentum

37. Motorcycle safety helmet extends the time of collision hence decreasing the
chance of collision
force acting
velocity
impulse

38. The collision between two bodies be elastic if bodies are
solid and soft
soft and elastic
solid and hard
hard and elastic

39. During long jump, athlete runs before taking the jump. By doing so he
provide him a larger inertia
decreases his inertia
decreases his momentum
increases his momentum

40. When car takes turn around a curve road, the passengers feel a force acting on them in a direction away from the center of the curve. It is due to
centripetal force
gravitational force
their inertia
centrifugal force

41. A body is falling freely under gravity. How much distance it falls during an interval of time between 1st and 2nd seconds of its motion, taking g=10?
14 m
20 m
5 m
25 m

42. What is the shape of velocity, time graph for constant acceleration?
straight inclined line.
parabola
inclined curve
declined curve

43. When collision between the bodies in a system is inelastic in nature then for system
momentum changes but K.E remain conserve
K.E changes but momentum remain conserve
both momentum and K.E changes
both momentum and K.E conserve

44. Which shows the correct relation between time of flight T and maximum height H?
H=gT2/8
H=8T2/g
H=8g/T2
H=gT2

45. The acceleration in the rocket at any instant is proportional to the nth power of the velocity of the expelled gases. Where the value of n must be?
-1
1
2
-2

46. Taking off rocket can be explained by
1st law of motion
2nd law of motion
Law of conservation of momentum
law of conservation of energy

47. Which of the following is not an example of projectile motion.
a gas filled ballon
bullet fired from gun
a football kicked
a base ball shot

48. What is the angle of projection for which the range and maximum height become equal?
tan-1 1/4
tan-1 4
tan-1 1/2
tan-1 2

49. The thrust on the rocket in the absence of gravitational force of attraction is
constant
not constant
constant if the rate of ejected gases is constant
constant for short range rocket.

50. When two bodies move toward each other with constant speeds the distance between them decreases at the rate of 6m / sec. If they move in the same direction the distance between them increases at the rate of 4m/sec. Then their speeds are
5m/s, 1m/s
3m/s, 3m/s
6m/s, 1m/s
4m/s, 2m/s