2025
NEET
MCQ
NEET 2025
$A B$ is a part of an electrical circuit (see figure). The potential difference " $V_A-V_B$ ", at the instant when current $i=2 \mathrm{~A}$ and is increasing at a rate of $1 \mathrm{amp} /$ second is:
A.
9 volt
B.
10 volt
C.
5 volt
D.
6 volt
2024
NEET
MCQ
NEET 2024 (Re-Examination)
Let us consider two solenoids $A$ and $B$, made from same magnetic material of relative permeability $\mu_r$ and equal area of cross-section. Length of $A$ is twice that of $B$ and the number of turns per unit length in $A$ is half that of $B$. The ratio of self inductances of the two solenoids, $L_A: L_B$ is
A.
$1: 2$
B.
$2: 1$
C.
$8: 1$
D.
$1: 8$
2023
NEET
MCQ
NEET 2023 Manipur
An emf is generated by an ac generator having 100 turn coil, of loop area $1 \mathrm{~m}^2$. The coil rotates at a speed of one revolution per second and placed in a uniform magnetic field of $0.05 \mathrm{~T}$ perpendicular to the axis of rotation of the coil. The maximum value of emf is :-
A.
3.14 V
B.
31.4 V
C.
62.8 V
D.
6.28 V
2023
NEET
MCQ
NEET 2023
The net magnetic flux through any closed surface is :
A.
Positive
B.
Infinity
C.
Negative
D.
Zero
2022
NEET
MCQ
NEET 2022 Phase 2
The magnetic flux linked to a circular coil of radius R is
$\phi = 2{t^3} + 4{t^2} + 2t + 5$ Wb
The magnitude of induced emf in the coil at t = 5 s is
A.
192 V
B.
108 V
C.
197 V
D.
150 V
2022
NEET
MCQ
NEET 2022 Phase 1
A square loop of side 1 m and resistance 1 $\Omega$ is placed in a magnetic field of 0.5 T. If the plane of loop is perpendicular to the direction of magnetic field, the magnetic flux through the loop is
A.
2 weber
B.
0.5 weber
C.
1 weber
D.
Zero weber
2021
NEET
MCQ
NEET 2021
Two conducting circular loops of radii R1 and R2 are placed in the same plane with their centres coinciding. If R1 >> R2, the mutual inductance M between them will be directly proportional to :
A.
${{R_2^2} \over {{R_1}}}$
B.
${{{R_1}} \over {{R_2}}}$
C.
${{{R_2}} \over {{R_1}}}$
D.
${{R_1^2} \over {{R_2}}}$
2019
NEET
MCQ
NEET 2019
A 800 turn coil of effective area 0.05 m2 is kept. perpendicular to a magnetic filed 5 × 10–5 T. When the plane of the coil is rotated by 90o around any of its coplanar axis in 0.1 s, the emf induced in the coil will be :
A.
0.2 V
B.
0.02 V
C.
2 V
D.
2 $ \times $ 10-3 V
2019
NEET
MCQ
NEET 2019
In which of the following devices, the eddy current effect is not used?
A.
magnetic braking in train
B.
electromagnet
C.
electric heater
D.
induction furnace
2017
NEET
MCQ
NEET 2017
A long solenoid of diameter 0.1 m has 2 $ \times $ 104 turns per meter. At the centre of the solenoid, a coil of 100 turns and radius 0.01 m is placed with its axis coinciding with the solenoid axis. The current in the solenoid reduces at a constant rate to 0 A from 4 A in 0.05 s. If the resistance of the coil is 10 $\pi $2 $\Omega $, the total charge flowing through the coil during this time is
A.
16 $\mu $C
B.
32 $\mu $C
C.
16$\pi $ $\mu $C
D.
32$\pi $ $\mu $C
2016
NEET
MCQ
NEET 2016 Phase 2
A uniform magnetic field is restricted within a region of rafius r. The magnetic field changes with time at a rate ${{d\overrightarrow B } \over {dt}}$. Loop 1 of radius R > r encloses the region r and loop 2 of radius R is outside the region of magnetic field as shown in the figure. Then the e.m.f. generated is
A.
zero in loop 1 and zero in loop 2
B.
$ - {{d\overrightarrow B } \over {dt}}\pi {r^2}$ in loop 1 and $ - {{d\overrightarrow B } \over {dt}}\pi {r^2}$ in loop 2
C.
$ - {{d\overrightarrow B } \over {dt}}\pi {R^2}$ in loop 1 and zero in loop 2
D.
$ - {{d\overrightarrow B } \over {dt}}\pi {r^2}$ in loop 1 and zero in loop 2
2016
NEET
MCQ
NEET 2016 Phase 1
A long solenoid has 1000 turns. When a current of 4 A flows through it, the magnetic flux linked with each turn of the solenoid is 4 $ \times \,{10^{ - 3}}$ Wb. The self-inductance of the solenoid is
A.
2 H
B.
1 H
C.
4 H
D.
3 H
2015
NEET
MCQ
AIPMT 2015
An electron moves on a straight line path XY as shown. The abcd is a coil adjacent to the path of electron. What will be the direction of current, if any, induced in the coil ?
A.
The current will reverse its direction as the electron goes past the coil
B.
No current induced
C.
abcd
D.
adcb
2014
NEET
MCQ
AIPMT 2014
A thin semicircular conducting ring (PQR) of radius r is falling with its plane vertical in a horizontal magnetic field B, as shown in the figure.
The potential difference developed across the ring when its speed is $v$, is
The potential difference developed across the ring when its speed is $v$, is
A.
zero
B.
${{Bv\pi {r^2}} \over 2}$ and P is at higher potential
C.
$\pi rBV$ and R is at higher potential
D.
2rBV and R is at higher potential
2013
NEET
MCQ
NEET 2013 (Karnataka)
A current of 2.5 A flows through a coil of inductance 5 H. The magnetic flux linked with the coil is
A.
0.5 Wb
B.
12.5 Wb
C.
zero
D.
2 Wb
2013
NEET
MCQ
NEET 2013
A wire loop is rotated in a magnetic field. The frequency of change of direction of the induced e.m.f. is
A.
four times per revoluation
B.
six times per revolution
C.
once per revolution
D.
twice per revolution
2012
NEET
MCQ
AIPMT 2012 Mains
In a coil of resistance 10 $\Omega $, the induced current developed by changing magnetic flux through it, is shown in figure as a function of time. The magnitude of change in flux through the coil in weber is
A.
8
B.
2
C.
6
D.
4
2012
NEET
MCQ
AIPMT 2012 Prelims
A coil of resistance 400 $\Omega $ is placed in a magnetic field. If the magnetic flux $\phi $ (Wb) linked with the coil varies with time t (sec) as $\phi = 50{t^2} + 4$.
The current in the coil at t = 2 sec is
The current in the coil at t = 2 sec is
A.
0.5 A
B.
0.1 A
C.
2 A
D.
1 A
2011
NEET
MCQ
AIPMT 2011 Prelims
The current $i$ in a coil varies with time as shown in the figure. The variation of induced emf with time would be
A.
B.
C.
D.
2010
NEET
MCQ
AIPMT 2010 Prelims
A conducting circular loop is placed in a uniform magnetic field, B = 0.025 T with its plane perpendicular to the loop. The radius of the loop is made to shrink at a constant rate of 1 mm s$-$1. The induced emf when the radius is 2 cm, is
A.
$2\pi \mu V$
B.
$\pi \mu V$
C.
${\pi \over 2}\mu V$
D.
2$\mu $$V$
2009
NEET
MCQ
AIPMT 2009
A conducting circular loop is placed in a uniform magnetic field 0.04 T with its plane perpendicular to the magnetic field. The radius of the loop starts shrinking at 2 mm/s. The induced emf in the loop when the radius is 2 cm is
A.
4.8$\pi $$\mu $V
B.
0.8$\pi $$\mu $V
C.
1.6$\pi $$\mu $V
D.
3.2$\pi $$\mu $V
2009
NEET
MCQ
AIPMT 2009
A rectangular, a square, a circular and an elliptical loop, all in the (x-y) plane, are moving out of a uniform magnetic field with a constant velocity. $\overrightarrow V = v\widehat i$. The magnetic field is directed along the negative z axis direction. The induced emf, during the passes of these loops, out of the field region, will not remain constant for
A.
The circular and the elliptical loops
B.
only the ellliptical loop
C.
any of the four loops
D.
the rectangular, circular and elliptical loops
2008
NEET
MCQ
AIPMT 2008
A long solenoid has 500 turns. When a current of 2 ampere is passed through it, the resulting magnetic flux linked with each turn of the solenoid is 4 $ \times $ 10$-$3 Wb. The self-inductance of the solenoid is
A.
1.0 henry
B.
4.0 henry
C.
2.5 henry
D.
2.0 henry
2008
NEET
MCQ
AIPMT 2008
A circular disc of radius 0.2 meter is placed in a uniform magnetic field of induction ${1 \over \pi }\left( {{{Wb} \over {{m^2}}}} \right)$ in such a way that its axis makes an angle of 60o with $\overrightarrow B .$ The magnetic flux linked with the disc is
A.
0.08 Wb
B.
0.01 Wb
C.
0.02 Wb
D.
0.06 Wb
2006
NEET
MCQ
AIPMT 2006
Two coils of self inductance 2 mH and 8 mH are placed so close together that the effective flux in one coil is completely linked with the other. The mutual inductance between these coils is
A.
16 mH
B.
10 mH
C.
6 mH
D.
4 mH
2005
NEET
MCQ
AIPMT 2005
As a result of change in the magnetic flux linked to the closed loop as shown in the figure, an e.m.f. $V$ volt is induced in the loop. The work done (joule) in taking a charge Q coulomb once along the loop is
A.
QV
B.
2QV
C.
QV/2
D.
zero
2004
NEET
MCQ
AIPMT 2004
The magnetic flux through a circuit of resistance R changes by an amount $\Delta $$\phi $ in a time $\Delta $t. Then the total quantity of electric charge Q that passes any point in the circuit during the time $\Delta $t is represented by
A.
$Q = {1 \over R}.{{\Delta \phi } \over {\Delta t}}$
B.
$Q = {{\Delta \phi } \over R}$
C.
$Q = {{\Delta \phi } \over {\Delta t}}$
D.
$Q = R.{{\Delta \phi } \over {\Delta t}}$
2001
NEET
MCQ
AIPMT 2001
For a coil having L = 2 mH, current flow through it is $I = {t^2}{e^{ - t}}$ then, the time at which emf become zero
A.
2 sec
B.
1 sec
C.
4 sec
D.
3 sec