Consider a magnet surrounded by a wire loop with an on/off switch $S$ as shown in the figure. If the switch is thrown from the off position (open circuit) to the on position (closed circuit), will a current flow in the circuit? Explain.

Vedclass pdf generator app on play store
Vedclass iOS app on app store
(N/A) No, a current will not flow in the circuit.
According to Faraday's law of electromagnetic induction, an induced electromotive force $(EMF)$ and consequently an induced current are produced only when there is a change in the magnetic flux linked with the coil.
In this scenario, the magnet is stationary relative to the wire loop. Even when the switch $S$ is closed, the magnetic field lines passing through the loop remain constant. Since there is no change in the magnetic flux $(\Delta \Phi = 0)$, no induced current is generated in the circuit.

Explore More

Similar Questions

$A$ rectangular coil of $20$ turns and an area of cross-section $25 \, cm^2$ has a resistance of $100 \, \Omega$. If a magnetic field which is perpendicular to the plane of the coil changes at the rate of $1000 \, T/s$,the current in the coil is $....... \, A$.

The magnetic field $B$ crossing normally a square metallic plate of area $4\,m^2$ changes with time as shown in the figure. The magnitude of the induced $emf$ in the plate during $t=2\,s$ to $t=4\,s$ is $..........\,mV$.

The magnetic flux linked to a circular coil of radius $R$ is given by $\phi = 2t^3 + 4t^2 + 2t + 5 \; Wb$. The magnitude of the induced $emf$ in the coil at $t = 5 \; s$ is $.......... \; V$.

The magnetic flux through a coil perpendicular to its plane is varying according to the relation $\phi = (5t^3 + 4t^2 + 2t - 5) \; Wb$. If the resistance of the coil is $5 \; \Omega$,then the induced current through the coil at $t = 2 \; s$ will be $.... \; A$. (in $.6$)

$A$ rectangular coil of $100$ turns and size $0.1 \,m \times 0.05 \,m$ is placed perpendicular to a magnetic field of $0.1 \,T$. If the field drops to $0.05 \,T$ in $0.05 \,s$, the magnitude of the e.m.f. induced in the coil is (in $\,V$)

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial
For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free
For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo