Q1
Allen
1. MAGNETIC FLUX
MCQ
'SI' unit of magnetic flux is :-
A.
ampere/meter $^{2}$
B.
weber
C.
gauss
D.
oersted
Q2
Allen
1. MAGNETIC FLUX
MCQ
A square coil of $0.01 \, m^{2}$ area is placed perpendicular to the uniform magnetic field of $10^{3} \, weber/m^{2}$ . The magnetic flux linked with the coil is :-
A.
10 weber
B.
$10^{-5}$ weber
C.
Zero
D.
100 weber
Q3
Allen
2. FARADAY LAW & LENZ'S LAW
MCQ
According to Faraday's Laws of electromagnetic induction:
A.
The direction of the induced current is such that it opposes itself
B.
The induced emf in the coil is proportional to the rate of change of magnetic flux associated with it
C.
The direction of induced emf is such that it opposes itself
D.
None of the above
Q4
Allen
2. FARADAY LAW & LENZ'S LAW
MCQ
A coil having an area of $2m^{2}$ is placed in a magnetic field which changes from 1 Weber/ $m^{2}$ to 4 Weber/ $m^{2}$ in 2 seconds. The e.m.f. induced in the coil will be:-
A.
4 volt
B.
3 volt
C.
2 volt
D.
1 volt
Q5
Allen
2. FARADAY LAW & LENZ'S LAW
MCQ
Magnetic field through a coil is changed with respect to time and an emf is induced in it. Select the incorrect statement regarding induced emf in coil :-
A.
Coil may be made up with wood
B.
Coil may be connected with an open circuit
C.
Coil must be of conducting nature
D.
Induced emf does not depends upon resistance of the coil
Q6
Allen
2. FARADAY LAW & LENZ'S LAW
MCQ
The current flows in a circuit as shown below. If a second circuit is brought near the first circuit then the current in the second circuit will be :-
A.
Clock wise
B.
Anti clock wise
C.
Depending on the value of $R_{G}$
D.
None of the above
Q7
Allen
2. FARADAY LAW & LENZ'S LAW
MCQ
A coil of resistance $10\Omega$ and 1000 turns have the magnetic flux line of $5.5 \times 10^{-4}$ Wb. If the magnetic flux changed to $5 \times 10^{-4}$ Wb. in 0.1 sec, then the induced charge in coil is:-
A.
$50 \mu C$
B.
$5 \mu C$
C.
$2 \mu C$
D.
$20 \mu C$
Q8
Allen
2. FARADAY LAW & LENZ'S LAW
MCQ
One coil of resistance $40\Omega$ is connected to a galvanometer of $160\Omega$ resistance. The coil has radius 6mm and turns 100. This coil is placed between the poles of a magnet such that magnetic field is perpendicular to coil. If coil is dragged out then the charge through the galvanometer is $32\mu C$ . The magnetic field is:-
A.
6.55 T
B.
5.66 T
C.
0.655 T
D.
0.566 T
Q9
Allen
2. FARADAY LAW & LENZ'S LAW
MCQ
A square loop of side 22 cm is changed to a circle in time 0.4 s. The magnetic field present is 0.2 T. The emf induced is :-
A.
-6.6 mV
B.
-13.2 mV
C.
+6.6 mV
D.
+13.2 mV
Q10
Allen
2. FARADAY LAW & LENZ'S LAW
MCQ
The magnetic flux in a coil of 100 turns increases by $12 \times 10^{3}$ Maxwell in 0.2 s due to the motion of a magnet. The emf induced in the coil will be:-
A.
$0.6\mathrm{mV}$
B.
$0.6\mathrm{V}$
C.
$6\mathrm{V}$
D.
$60\mathrm{V}$
Q11
Allen
2. FARADAY LAW & LENZ'S LAW
MCQ
A closed coil consists of 500 turns on a rectangular frame of area $4.0 \, \text{cm}^2$ and has a resistance of 50 ohms. The coil is kept with its plane perpendicular to a uniform magnetic field of $0.2 \, \text{wb/m}^2$ , the amount of charge flowing through the coil if it is turned over (rotated through $180^\circ$ ):-
A.
$1.6 \times 10^{-3} \, \text{C}$
B.
$16 \times 10^{-3} \, \text{C}$
C.
$0.16 \times 10^{-3} \, \text{C}$
D.
$160 \times 10^{-3} \, \text{C}$
Q12
Allen
2. FARADAY LAW & LENZ'S LAW
MCQ
A coil of mean area $500 \, cm^{2}$ and having 1000 turns is held perpendicular to a uniform field of 0.4 gauss. The coil is turned through $180^{\circ}$ in $\frac{1}{10}$ second. The average induced e.m.f.:-
A.
0.04 V
B.
0.4 V
C.
4 V
D.
0.004 V
Q13
Allen
2. FARADAY LAW & LENZ'S LAW
MCQ
An emf is induced in a coil. The linking magnetic flux
A.
Must be decreasing
B.
Must be increasing
C.
Must remain constant
D.
Can be either increasing or decreasing
Q14
Allen
2. FARADAY LAW & LENZ'S LAW
MCQ
Consider a metal ring kept on a horizontal plane. A bar magnet is held above the ring with its length along the axis of the ring. If the magnet is dropped freely the acceleration of the falling magnet is (g is acceleration due to gravity) :-
A.
More than g
B.
Equal to g
C.
Less than g
D.
Depend on mass of magnet
Q15
Allen
2. FARADAY LAW & LENZ'S LAW
MCQ
An electron beam is moving near to a conducting loop then the induced current in the loop :-
A.
clockwise
B.
anticlockwise
C.
both
D.
no current
Q16
Allen
2. FARADAY LAW & LENZ'S LAW
MCQ
The current flows from A to B as shown in the figure. The direction of the induced current in the loop is: -
A.
clockwise
B.
anticlockwise
C.
straight line
D.
none of these
Q17
Allen
2. FARADAY LAW & LENZ'S LAW
MCQ
Faraday law represents :-
A.
relation between I and B
B.
relation between magnetic force and magnetic field
C.
relation between e.m.f and rate of change of flux
D.
none of these
Q18
Allen
2. FARADAY LAW & LENZ'S LAW
MCQ
An aluminium ring B faces an electromagnet A. The current I through A can be altered. Then which of the following statement is correct :-
A.
If I decreases A will repel B
B.
Whether I increases or decreases, B will not experience any force
C.
If I increases, A will repel B
D.
If I increases, A will attract B
Q19
Allen
2. FARADAY LAW & LENZ'S LAW
MCQ
A charge particle moves along the line AB, which lies in the same plane of a circular loop of conducting wire as shown in the fig. Then :-
A.
No current will be induced in the loop
B.
The current induced in the loop will change its direction as the charged particle passes by
C.
The current induced will be anticlockwise
D.
The current induced, will be clockwise
Q20
Allen
2. FARADAY LAW & LENZ'S LAW
MCQ
The magnetic flux through a circuit of resistance R changes by an amount $\Delta\phi$ in a time $\Delta t$ . The total quantity of electric charge Q that passes any point in the circuit during the time $\Delta t$ is represented by:-
A.
$Q = \frac{\Delta\phi}{R}$
B.
$Q = \frac{\Delta\phi}{\Delta t}$
C.
$Q = R \cdot \frac{\Delta\phi}{\Delta t}$
D.
$Q = \frac{1}{R} \cdot \frac{\Delta\phi}{\Delta t}$
Q21
Allen
2. FARADAY LAW & LENZ'S LAW
MCQ
If number of turns of $70cm^{2}$ coil is 200 and it is placed in a magnetic field of $0\cdot8~Wb/m^{2}$ which is perpendicular to the plane of coil and it is rotated through an angle $180^{\circ}$ in $0\cdot1$ sec, then induced emf in coil:
A.
11.2 V
B.
1.12 V
C.
22.4 V
D.
2.24 V
Q22
Allen
2. FARADAY LAW & LENZ'S LAW
MCQ
A circular loop of radius r is placed in a region where magnetic field increases with respect to time as $B(t) = at$ then induced emf in coil :
A.
$\pi r^{2}a$
B.
$3\pi r^{2}a$
C.
$2\pi r^{2}a$
D.
$4\pi r^{2}a$
Q23
Allen
2. FARADAY LAW & LENZ'S LAW
MCQ
A circular loop of radius r is moved away from a current carrying wire then induced current in circular loop will be :-
A.
Clock wise
B.
Anti clockwise
C.
Not induced
D.
None of them
Q24
Allen
3. SELF INDUCTION AND L–R DC CIRCUIT
MCQ
When the current through a solenoid increases at a constant rate, the induced current
A.
is a constant and is in the direction of the inducing current
B.
is a constant and is opposite to the direction of the inducing current
C.
increase with time and is in the direction of the inducing current
D.
increase with time and opposite to the direction of the inducing current
Q25
Allen
3. SELF INDUCTION AND L–R DC CIRCUIT
MCQ
A solenoid of 10 henry inductance and 2 ohm resistance, is connected to a 10 volt battery. In how much time the magnetic energy will reach to 1/4th of the maximum value?
A.
3.5 sec
B.
2.5 sec
C.
5.5 sec
D.
7.5 sec