(B) The induced emf $\varepsilon$ is given by Faraday's law of induction: $|\varepsilon| = |\frac{d\phi}{dt}| = |\frac{d(B \cdot A)}{dt}|$. Since the

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(B) The induced emf $\varepsilon$ is given by Faraday's law of induction: $|\varepsilon| = |\frac{d\phi}{dt}| = |\frac{d(B \cdot A)}{dt}|$. Since the area $A$ is constant,$|\varepsilon| = A \cdot |\frac{dB}{dt}|$. Given $A = 0.2 \, m^2$,initial $B = 0.25 \, T$,final $B = 0 \, T$,and $\Delta t = 10^{-4} \, s$. $|\varepsilon| = 0.2 \cdot \frac{0.25 - 0}{10^{-4}} = 0.2 \cdot 2500 = 500 \, V$. The induced current $I$ is given by Ohm's law: $I = \frac{\varepsilon}{R}$. Given $R = 20 \, \Omega$,$I = \frac{500}{20} = 25 \, A$.

Class 12 Physics Electromagnetic Induction Faraday's and Lenz's Law

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$A$ wire loop of area $0.2 \, m^2$ has a resistance of $20 \, \Omega$. $A$ magnetic field pointing normal to the loop has a magnitude of $0.25 \, T$ and is reduced to zero at a uniform rate in $10^{-4} \, s$. What is the induced emf and the resulting current?

TS EAMCET 2022 All TS EAMCET

A
$50 \, V, 2.5 \, A$
B
$500 \, V, 25 \, A$
C
$250 \, V, 12.5 \, A$
D
$500 \, V, 2.5 \, A$

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Electromagnetic Induction

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Faraday's and Lenz's Law

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$A$ wire loop of area $0.2 \, m^2$ has a resistance of $20 \, \Omega$. $A$ magnetic field pointing normal to the loop has a magnitude of $0.25 \, T$ and is reduced to zero at a uniform rate in $10^{-4} \, s$. What is the induced emf and the resulting current?

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Assertion: An $emf$ $\vec{E}$ is induced in a closed loop where magnetic flux is varied. The induced $\vec{E}$ is not a conservative field.Reason: The line integral $\oint \vec{E} \cdot d\vec{l}$ around the closed loop is nonzero.

The magnetic flux through a stationary loop with resistance $R$ varies during an interval of time $T$ as $\phi = at(T - t)$. The heat generated during this time,neglecting the inductance of the loop,will be

The magnitude of flux linked with a coil varies with time as $\phi = 3t^2 + 4t + 7$. The magnitude of the induced e.m.f. at $t = 2 \ s$ is: (in $V$)

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Assertion: An $emf$ $\vec{E}$ is induced in a closed loop where magnetic flux is varied. The induced $\vec{E}$ is not a conservative field.
Reason: The line integral $\oint \vec{E} \cdot d\vec{l}$ around the closed loop is nonzero.