MCAT MCQ Quiz Hub

1. The ration stress to strain in youngs modulus of the material then tension is
Directly proportional to extension.
Directly proportional to strain.
Directly proportional to square of amplitude.
Inversely proportional to extension

2. Materials that undergo plastic deformation before breaking are called
Brittle
Ductile
Amorphous
Polymers

3. A wire is stretched by a force F which causes an extension 1. The energy stored in the wire is
The extension of the wire is proportional to the force applied
The weight of the wire is negligible
The wire is not stretched beyond its elastic limit
The cross sectional area of the wire remains constant

4. A wire obeys Hooks law is of length 11 when it is in equilibrium under a tension F1. Its length becomes 12 when the tension is increased to F2. The energy stored in the wire during this process is
(F1+F2) (121+122)
(F1+F2) (122-112)
(F1+F2) (12-11)
(F1+F2) (12-11)

5. Formation of large molecule by joining small molecules is
Fusion
Polymerization
Crystallization
Subtraction

6. Any alteration produced in shapes length or volume when a body is subjected to some external force is called
Stiffness
Toughness
Extension
Deformation

7. The energy band occupied by the valence electrons is called
Energy state
Valence band
ve energy state
conduction band

8. The curie temperature is that at which
Semi-conductor becomes conductors
Ferromagnetic becomes paramagnetic
Paramagnetic becomes diamagnetic
Metals become super conductor

9. A ferromagnet will become fully magnetized at
High voltage A.C
Low voltage A.C
Alternating current at its peak value
D.C current at peak value

10. Coercive force is the force which opposes
Demagnetization
Breakage
Extension
Surface cracking

11. Materials in which valence electrons are tightly bound to their atoms at low temperature are called
Semi conductor
Super conductors
Insulators
Conductor

12. The bulk properties of materials such as their mode of fracture can be related to their
Polymerization
Cleavage
Microstructure
Dislocation

13. The angular position of cells remains the same for a sample of a crystal. This property is called
Isotropy
Cleavage
Homogeneity
The external symmetry of form

14. The breaking of crystals along definite direction is called
Cleavage
Symmetry
Isotropy
Homogeneity

15. If the density of atoms remain same along any direction in a crystal is called
Symmetry
Homogeneity
Isotropy
Cleavage

16. In simple cube one atom or molecule lies at its
Force corners
Nine corners
Eight corners
Six corners

17. The band theory of solids explains satisfactorily the nature of
Electrical insulators alone
Electrical conductors alone
Electrical semi conductors alone
All of the above

18. A vacant or partially filled band is called
Conduction band
Valence band
Forbidden band
Empty band

19. A completely filled band is called
Conduction band
Valence band
Forbidden band
Core band

20. The electrons in conduction band are free to
Transport vibrations
Transport signals
Transport charge
Transport impulses

21. Which one has the greatest energy gap ?
Semi conductor
Conductor
Metals
Non metals

22. Many of the semi conductors are crystals of the type
Face centred cubic
Body centred cubic
Simple cubic
All of the above

23. With increase in temperature the electrical conductivity of intrinsic semi conductor
Decreases
Increases
Remains same
First increases then decreases

24. Holes can exist in
Conductors
Insulators
Semi conductors
All of the above

25. On the basis of band theory of solids the semiconductors have
A party filled valence band and totally empty conduction band
A completely filled valence band a totally empty conduction band and a very wide forbidden band
A completely filled valence band a partially filled conduction band and a narrow forbidden band
A partly filled valence band a totally empty conduction band and a wide forbidden band

26. In a semiconductors the charge carriers are
Holes only
Electrons only
Electron and holes both
All of the above

27. The net charge on n-type material is
Positive
Negative
Both positive and negative
Neutral

28. Very weak magnetic fields are detected by
Squids
Magnetic resonance imaging (MRI)
Magnetometer
Oscilloscope

29. Energy needed to magnetize and demagnetize is represented by
Hysteresis curve
Hysteresis loop area
Hysteresis loop
Straight line

30. Ratio of the weight of H-atom to that of an electron is approximately
18.336
1836
18360
183.6

31. Photon of highest frequency will be absorbed when transition takes place from
1st to 5th orbit
2nd to 5th orbit
3rd to 5th orbit
4th to 5th orbit

32. In hydrogen spectrum which one of the following series lies in the ultraviolet region?
Balmer series
Pfund series
Bracket series
Lymann series

33. In obtaining an X-ray photograph of our hand we use the principle of
photo electric effect
ionization
shadow photograph
any of above

34. Excited atoms return to their ground state in
10-10s
10-8s
10-6s
10-9s

35. When we excite some atoms by heat collision or electrical discharge they will
radiate electromagnetic energy with a continuous distribution of wavelength
absorb particular wavelengths when white light is incident on them
radiate electromagnetic energy of discrete characteristic wavelength
emit either invisible or visible light

36. Hydrogen atom does not emit X-rays because
its energy levels are too close to each other
its energy levels are too far apart
it is too small in size
it has a single electron

37. Which one of following postulate is in accordance with the Rutherfords model?
continuous spectra for atoms
discrete spectra for atoms
either continuous nor discrete
no spectrum

38. X-ray are
of unknown nature
high energy electrons
high energy photons
radio isotopes

39. Tick the correct statement
an atom has limited number of ionization potentials but a large number of excitation potentials
there are as many excitation potentials as there are excited states
the difference between the energy of the ground sate and any one of the excited states is the measure of excitation energy
all of above

40. Ground state energy of the 4th orbit in a H-atom is
?13.60 eV
?3.40 eV
?0.85 eV
?1.51 eV

41. Total number of series in hydrogen spectrum is
three
four
five
six

42. The radiations emitted form hydrogen filled discharge tube show
band spectrum
line spectrum
continuous spectrum
absorption spectrum

43. The electric P.E of an electron in an orbit at a distance rn from the positive charge
Ke2/rn
Ke2/rn2
?Ke2/rn
?Ke2/rn2

44. Radiation with wavelength longer than red lights
ultraviolet rays
X-rays
infra red radiation
visible radiation

45. Bracket series is obtained when all transition of electron terminate on
4th orbit
5th orbit
3rd orbit
2nd orbit

46. In an electronic transition atom cannot emit
?-rays
infra red radiation
visible light
ultraviolet rays

47. Reverse process of photoelectric effect is
pair production
Compton effect
annihilation of matter
X-rays production

48. X-rays are similar in nature to
cathode rays
positive rays
?-rays
?-rays

49. The penetrating power of X-rays depends on their
applied voltage
frequency
source
all of the above

50. When X-rays are passed through successive aluminum sheets what happens to their thickness?
increases
it decreases
it remains same
sometimes increases and sometimes decreases