back to directory
NEET PHYSICSELECTROMAGNETIC INDUCTIONEasy

Question

A big circular coil with 10001000 turns and an average radius of 10 m10 \text{ m} is rotating about its horizontal diameter at a rate of 2 rad s12 \text{ rad s}^{-1}. The vertical component of the Earth's magnetic field at that location is 2×105 T2 \times 10^{-5} \text{ T}, and the electrical resistance of the coil is 12.56Ω12.56 \Omega. The maximum induced current in the coil will be:

A

2 A

B

0.25 A

C

1.5 A

D

1 A

Step-by-Step Solution

The maximum induced electromotive force (εmax\varepsilon_{max}) in a rotating coil is given by the formula εmax=NBAω\varepsilon_{max} = NBA\omega, where: NN is the number of turns (10001000). BB is the magnetic field (2×105 T2 \times 10^{-5} \text{ T}). AA is the area of the coil (πr2=π(10)2=100π m2\pi r^2 = \pi (10)^2 = 100\pi \text{ m}^2). ω\omega is the angular velocity (2 rad s12 \text{ rad s}^{-1}).

The maximum induced current (ImaxI_{max}) is given by Ohm's law: Imax=εmaxRI_{max} = \frac{\varepsilon_{max}}{R}.

Substituting the values: Imax=1000×(2×105)×(100π)×212.56I_{max} = \frac{1000 \times (2 \times 10^{-5}) \times (100\pi) \times 2}{12.56}

Noting that 12.564π12.56 \approx 4\pi: Imax=1000×2×105×100π×24πI_{max} = \frac{1000 \times 2 \times 10^{-5} \times 100\pi \times 2}{4\pi} Imax=400000π×1054πI_{max} = \frac{400000 \pi \times 10^{-5}}{4\pi} Imax=4π4π=1 AI_{max} = \frac{4\pi}{4\pi} = 1 \text{ A}.

Exam Context & Concepts Covered

This question aligns with the NEET PHYSICS syllabus, specifically targeting concepts from ELECTROMAGNETIC INDUCTION. Mastering this topic is crucial for scoring well in the upcoming medical entrance examinations. Solving conceptually related problems will help you understand the nuances of these concepts and improve your problem-solving speed.

PHYSICSELECTROMAGNETIC INDUCTIONcircularaverageradiusrotatinghorizontal

More ELECTROMAGNETIC INDUCTION Questions

View all

A conducting circular loop of face area $2.5 \times 10^{-3} \text{ m}^2$ is placed perpendicular to a magnetic field which varies as $B=0.5 \sin(100\pi t) \text{ T}$. The magnitude of induced EMF at time $t=0 \text{ s}$ is:

A.$0.125\pi \text{ mV}$
B.$125\pi \text{ mV}$
C.$125\pi \text{ V}$
D.$12.5\pi \text{ mV}$
MediumSolve

A coil of resistance $400\Omega$ is placed in a magnetic field. If the magnetic flux $\phi\;(\text{Wb})$ linked with the coil varies with time $t\;(\text{sec})$ as $\phi=50t^2+4$. The current in the coil at $t=2\text{s}$ is:

A.0.5A
B.0.1A
C.2A
D.1A
EasySolve

A wooden stick of length $3l$ is rotated about an end with constant angular velocity $\omega$ in a uniform magnetic field $B$ perpendicular to the plane of motion. If the upper one third of its length is coated with copper, the potential difference across the whole length of the stick is:

A.$\frac{9B\omega l^2}{2}$
B.$\frac{4B\omega l^2}{2}$
C.$\frac{5B\omega l^2}{2}$
D.$\frac{B\omega l^2}{2}$
MediumSolve

The primary and secondary coils of a transformer have 50 and 1500 turns respectively. If the magnetic flux $\phi$ linked with the primary coil is given by $\phi = \phi_0 + 4t$, where $\phi$ is in Weber, $t$ is time in seconds, and $\phi_0$ is a constant, the output voltage across the secondary coil is:

A.90 V
B.120 V
C.220 V
D.30 V
EasySolve

In which of the following devices, the eddy current effect is not used?

A.Electric heater
B.Induction furnace
C.Magnetic braking in train
D.Electromagnet
EasySolve

The current in an inductor of self-inductance $4 \text{ H}$ changes from $4 \text{ A}$ to $2 \text{ A}$ in $1 \text{ s}$. The emf induced in the coil is:

A.-2 V
B.2 V
C.-4 V
D.8 V
EasySolve

In the above diagram, a strong bar magnet is moving towards solenoid-2 from solenoid-1. The direction of induced current in solenoid-1 and that in solenoid-2, respectively, are through the directions:

A.$B \to A$ and $C \to D$
B.$A \to B$ and $C \to D$
C.$B \to A$ and $D \to C$
D.$A \to B$ and $D \to C$
MediumSolve

A rod of length $L$ rotates with a small uniform angular velocity $\omega$ about its perpendicular bisector. A uniform magnetic field $B$ exists parallel to the axis of rotation. The potential difference between the centre of the rod and an end is:

A.$\frac{B\omega L^2}{8}$
B.$\frac{B\omega L^2}{2}$
C.$\frac{B\omega L^2}{4}$
D.zero
EasySolve

This neet physics practice question is part of the TopperSquare free question bank. TopperSquare offers 15,000+ chapter-wise NEET MCQs across Physics, Chemistry, and Biology with detailed step-by-step explanations, full mock tests, NEET PYQs (2010–2024), and an AI-powered performance analytics dashboard. browse all neet practice questions → · practice physics sets →