Paper for Entry Test Preparation
Physics 2nd year Chapter No. 14
Total marks:- 200 Time
allowed 40 minutes
Note:- Fill
the appropriate answer of the following questions in the answer sheet. Double
filling and erasing is not allowed. Each question carries equal marks and for
each wrong answer minus one is awarded.
1) In the region surrounding a current carrying
wire:
a)
A magnetic field is set up b)
The lines of force are elliptical
c)
Direction of lines of force depends upon direction of current d) All of these
2) A current carrying conductor sets up its own:
a)
Electric field b)
Nuclear field c)
Magnetic filed d) Both
(a) and (c)
3) The pointer of a magnetic compass:
a)
Is affected only by permanent magnets b)
Aligns itself parallel to the applied magnetic field
c)
Vibrates in the magnetic field of the current d)
Aligns itself perpendicular to the magnetic field
4) The direction of magnetic lines of force around a
current carrying wire is given by:
a)
Faraday’s law b) Head
to tail rule c) Right
hand rule d) Both (a)
and (b)
5) Magnetic lines of force:
a)
Cannot intersect at all b)
Intersect at infinity c)
Intersect within magnet d) Intersect
at neutral points
6) A current is passed through a straight wire. The
magnetic field established around it has its lines of force:
a)
Circular and endless b) Oval in
shape and endless c) Straight d) Parabolic
7) The direction of force experienced by a current
carrying conductor placed in a magnetic field B is found by:
a)
Dot product of L and B b) Cross
product of L and B c) Right hand rule d) Both (b) and (c)
8) Vector area A is a vector whose direction:
a)
Is along the surface element b)
Perpendicular to surface element
c)
At an angle 60o to the surface element d) Depends upon the direction of magnetic field
9) If the field is directed along the normal to the
area, then flux is:
a)
Maximum b)
Equal to zero c)
Equal to BA d)
Minimum
10) Magnetic induction is defined as flux per unit
area of the surface which is:
a)
Parallel to B b)
Perpendicular to B c) At an
angle 60o to B d)
Any of (a) or (b)
11) Tesla can also be written as:
a)
NAm-1 b)
NA-1m-1 c)
N-1Am-1 d)
NA-1m
12) Magnetic flux density at any point due to
current carrying conductor can be computed by:
a)
Ampere’s law b)
Faraday’s law c)
Lenz’s law d)
Newton’s law
13) A solenoid is a coil of wire which is:
a)
Short, loosely, wound, cylindrical b)
Long, tightly wound, spherical
c)
Long, loosely wound, cylindrical d)
Long, tightly wound, cylindrical
14) In the formula B = mo
nI, the symbol ‘n’ denotes:
a)
Total number of turns of solenoid b)
Number of turns per unit length
c)
Number of turns per unit volume d)
Number of turns per unit area
15) The magnetic filed inside a solenoid can by increased
by:
a)
Increasing ‘n’ b)
Decreasing ‘I’ c)
Increasing ‘I’ d)
Both (a) and (c)
16) The permeability of free space is measured in:
a)
Wb/Am b) Wb
A/m c) Am/N d) Nm/A
17) Magnetic flux passing through an element of area
A placed perpendicular to a uniform magnetic field B is:
a)
Maximum b)
Minimum c) Zero d) Very
small
18) When the charged particle is projected at right
angles to the field, then force experienced by it will be:
a)
Maximum b) Zero c) qvB d) Both (a)
and (c)
19) When an electric charge ‘q’ is placed in an
electric field, it will experience a force:
a)
Parallel to electric field b)
Perpendicular to electric field
c)
At an angle 60o to electric field d)
All of these
20) Lorentz force means force acting on a particle
which is:
a)
Sum of electric and magnetic forces b)
Electric force only
c)
Magnetic force only d)
Product of electric and magnetic force only
21) Unit of evB is:
a)
Coulomb b)
Ampere c)
Newton d)
Weber
22) When an electron enters at right angles to a
magnetic field, the magnitude of its velocity:
a)
Increases b)
Decreases c)
Remains unchanged d) Either (a)
or (b)
23) The apparatus which makes the electronic
trajectory visible uses:
a)
Nitrogen at low pressure b) Hydrogen
at low pressure c) Oxygen at high
pressure d) Hydrogen
at high pressure
24) Alpha particles are made to pass through a
device called velocity selector. The velocity of α-particles can be found by:
a)
v = EB b)
v = E/B c) v
= B/E d) v
= E + B
25) CRO works by deflecting the beam of electrons as
they pass through:
a)
Uniform electric field b/w two sets of parallel plates b) Non uniform magnetic field
c)
Three sets of parallel plates d)
Uniform magnitude field
26) An electron gun consists of:
a)
Indirectly heated cathode and a grid b)
Three anodes
c)
Directly heated cathode d)
Both (a) and (b)
27) Indirectly heated cathode means that the:
a)
Cathode heats the filament b)
Grid heats the filament
c)
Filament heats the cathode d)
Any of these
28) The anodes in CRO are at:
a)
Higher potential w.r.t. cathode b)
Lowe potential w.r.t. cathode
c)
Same potential as cathode d)
Non of these
29) Voltage applied across the x-plates deflects the
beam:
a)
Vertically on the screen b)
Horizontally on the screen c) At 60o
to the horizontal d) At
30oto the horizontal
30) The output waveform of time base generator is:
a)
Sinusoidal b)
Elliptical c)
Saw-toothed d)
Circular
31) Synchronization controls of CRO are used to
synchronize the:
a)
Voltage b)
Frequencies c)
Periods d)
Both (b) and (c)
32) By CRO we can determine:
a)
Instantaneous voltage b) Peak
voltage c) Peak
current d) Both (a)
and (b)
33) The phase difference b/w two voltages can be
obtained by displaying their waveform:
a)
Simultaneously b) Instantaneously c) Turn by turn d) Either (a) or (b)
34) If current is flowing upward in a wire (parallel
to wall) placed in a magnetic filed (west to east), then it will experience a
force directed:
a)
East b)
North c)
South d)
West
35) The coil of galvanometer is suspended b/w poles
of a U-shaped magnet which are:
a)
Plane-shaped b)
Convex shaped c) Concave
shaped d) Any of these
36) The rectangular coil of the galvanometer is made
of:
a)
Copper wire b)
Enameled copper wire c) Enameled
steel wire d) Steel wire
37) To make the field stronger near the coil of
galvanometer, we place inside the coil a:
a)
Hard aluminium cylinder b) Soft copper
cylinder c) Soft iron cylinder d) Tungsten cylinder
38) A moving coil galvanometer is based on the following
effect of current:
a)
Chemical b)
Magnetic c)
Heating d)
Touching
39) Radial magnetic field is used in a galvanometer
so that galvanometer scale is:
a)
Logarithmic b)
Linear c)
Exponential d)
Both (a) and (c)
40) When the coil of the galvanometer comes to rest,
then the deflecting torque is:
a)
Equal to restoring couple b)
Greater than restoring couple
c)
Smaller than the restoring couple d)
Any of these
41) A moving coil galvanometer is based on the:
a)
Magnetic effect of current b) Heating
effect of current c) Chemical effect
of current d) Both (a) and (c)
42) To increase sensitivity of a galvanometer:
a)
‘c’ may be decreased b) ‘B’ may
be increased c) Area ‘A’ may be
decreased d) Both (a) and (b)
43) Dead beat galvanometer is so called because it
is:
a)
Unstable b)
Always dead c)
Stable d)
Both (b) and (c)
44) Most meter movement give full scale deflection
with a current of:
a)
A few mA only b) A few mA only c)
A few amperes only d) All of
these
45) The resistance of the shunt is:
a)
Very small b)
Very large c)
Large d)
Extremely large
46) A voltmeter is connected:
a)
Always in series with the circuit b)
Always in parallel with the circuit
c)
Sometimes in series and sometimes in parallel d)
Any of above
47) When the terminals ‘c’ and ‘d’ of an ohmmeter
are connected with each other, the pointer rests on the scale at the:
a)
Extreme right b)
Zero ohm c)
Zero ohm d)
100 ohm
48) The zero of the scale of an ohmmeter is marked
at its:
a)
Extreme left end b) Extreme
right end c) Center d) Any of
these
49) A proper combination of a galvanometer and shunt
acts as:
a)
An ohmmeter b) A
voltmeter c) An
ammeter d) Any of
these
50) An avometer measures:
a)
D.C voltage only b) A.C
voltages only c) Currents
only d) All of these
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