1: Which method can be used to distinguish between the two types of carriers
a. Hall effect
b. Rayleigh method
c. Doppler effect
d. Fermi effect
2: Current is flowing in two long parallel conductors in the same direction. The conductors · · · each other
a. Are inclined to
b. Repel
c. Attract
d. Neither attract nor repel
3: Cathode rays enter in a uniform magnetic field perpendicular to direction of field. In magnetic field their path will be
a. Circle
b. Parabolic
c. Straight line
d. Elliptical
4: The force experienced by a charged particle in magnetic field is maximum when particle move in a direction
a. Perpendicular to
b. Parallel to
c. Is at rest
d. None of these
5: A particle moving in a magnetic field has an increase in its velocity then its radius of circle
a. Becomes half
b. Increases
c. Decreases
d. Remains same
6: If relative permeability of a substance is 0.79, then it is · · · material
a. Diamagnetic
b. Paramagnetic
c. Ferromagnetic
d. None of these
7: An electron enters a magnetic field acting vertically downward with a velocity v from east. The electron is deflected along
a. South
b. North
c. Southeast
d. Northeast
8: A charged particle moves through a magnetic field in a direction perpendicular to it. Then · · · remains unchanged
a. Direction
b. Speed
c. Velocity
d. Acceleration
9: Magnetic dipole moment is defined as
a.
b.
c. µ = IA
d. None of these
10: Which define the relation between magnetic torque and magnetic dipole moment
a.
b.
c.
d. None of these
11: Resistivity (Ohm – m) of semiconductor varies
a.
b.
c.
d.
12: Semiconductor compound is
a. Germanium
b. Sodium Chloride
c. Gallium Arsenide
d. Sodium Phosphate
13: Orbital of valance conducting band overlap in
a. Metals
b. Semiconductors
c. Conductors
d. Semi-metals
14: At 0K the valance band in intrinsic semiconductor is
a. Completely filled
b. Complete empty
c. Partially filled
d. Almost filled
15: In intrinsic semiconductor rate of generation of carrier’s ‘g” depends on
a. Volume
b. Temperature
c. Pressure
d. Entropy
16: Popping ratio is
a.
b.
c.
d.
17: N-type semiconductors are made by adding
a. Group III
b. Group VI
c. Period III
d. Period VI
18: Both n and p type doping are charged
a. Neutral
b. Positive
c. Negative
d. Region dependent
19: With increasing depth in valance band the hole probability. . ..
a. Increases exponentially
b. Decreases exponentially
c. Increases linearly
d. Decreases linearly
20: Current density and drift velocity depends on
a. External electric field
b. External magnetic field
c. Both
d. Independent
21: The strongest diamagnetic material is
a. Bismuth
b. Hydrogen
c. Helium
d. Neon
22: The temperature at which ferromagnetic material changes into paramagnetic material is known as
a. Critical temp
b. Temp. inversion
c. Debye temp
d. Curie’s temp.
23: Which of the following magnetic substance can have positive permeability and negative susceptibility
a. Ferromagnetic
b. Paramagnetic
c. Diamagnetic
d. None
24: The susceptibility of diamagnetic material is
a. Very large
b. Small but positive
c. Small but negative
d. Zero
25: Paramagnetic susceptibility varies as
a. T
b.
c.
d.
26: Curie-Weiss law is
a.
b.
c.
d.
27: Which of the following is diamagnetic
a. Water
b. Air
c. Copper sulphate
d. Liquid oxygen
28: The relation between magnetic susceptibility and relative permeability is
a.
b.
c.
d.
29: The relative permeability of air is
a. 1
b. 1.3
c. 0.5
d. 2
30: The most suitable material for making permanent magnet is
a. Nickel
b. Copper
c. Steel
d. Soft iron
31: Superconductivity was first discovered by
a. Meissner and Schoenfeld
b. C.H. Townes
c. H. Kamerlingh Onnes
d. C.A. Reynolds
32: The metal mercury becomes superconductor at
a.
b.
c.
d.
33: A superconductor has
a. Zero conductivity
b. Infinite resistivity
c. Infinite conductivity
d. None
34: Magnetic susceptibility of superconductors is given by
a.
b.
c.
d.
35: The temperature at which a metal becomes super-conducting is called
a. Neel temp
b. Curie’s temp
c. Meissner point
d. Transition temp
36: Superconductivity is usually exhibited at temperatures
a. Low
b. High
c. Very high
d. None of these
37: Which of the property is not exhibited by superconductors
a. µr = 0
b. Copper loss = 0
c.
d.
38: According to isotope effect, the transition temperature Tc for superconductor is proportional to
a.
b.
c.
d.
39: BCS theory is an attempt to explain
a. Magnetism
b. Superconductivity
c. Thermoelectric effect
d. Heating effect
40: In a particular superconductor, transition takes place gradually, it belongs to
a. Type-I
b. Type-II
c. Type-I and Type-II both
d. None of these