CBSE 2023 · Region 3 · Set 3 · Q28 · 3 marks
The figure shows a rectangular conductor PQRS in which the arm PQ of length $\displaystyle 10$ cm and resistance $\displaystyle 0 \cdot 4 \Omega$ is free to move. It is kept in a uniform magnetic field $\displaystyle \mathrm{B}=0 \cdot 2 \mathrm{~T}$ acting perpendicular into the plane of PQRS . If $\displaystyle \operatorname{arm} \mathrm{PQ}$ is moved with a velocity v of $\displaystyle 5 \mathrm{~cm} / \mathrm{s}$ as shown, find :
(a)the current induced in the loop, and(b)the power required to move the arm. (Resistances of arms PS, SR and RQ are negligible.)
The figure shows a rectangular conductor PQRS in which the arm PQ of length $\displaystyle 10$ cm and resistance $\displaystyle 0 \cdot 4 \Omega$ is free to move. It is kept in a uniform magnetic field $\displaystyle \mathrm{B}=0 \cdot 2 \mathrm{~T}$ acting perpendicular into the plane of PQRS . If $\displaystyle \operatorname{arm} \mathrm{PQ}$ is moved with a velocity v of $\displaystyle 5 \mathrm{~cm} / \mathrm{s}$ as shown, find :
(a)
the current induced in the loop, and
(b)
the power required to move the arm. (Resistances of arms PS, SR and RQ are negligible.)
Marking-scheme solution
Finding the
(a)
\[\begin{aligned}
& i=\frac{\mathrm{B} l \mathrm{v}}{R} \\
& =\frac{0.2 \times\left(10 \times 10^{-2}\right) \times\left(5 \times 10^{-2}\right)}{0.4} \\
& i=2.5 \times 10^{-3} \mathrm{~A}
\end{aligned}
\]
(b)
\[\begin{aligned}
& P=i^{2} R \\
& =\left(2.5 \times 10^{-3}\right)^{2} \times 0.4 \\
& P=2.5 \times 10^{-6} \mathrm{~W}
\end{aligned}
\]
Electromagnetic InductionMotional Electromotive ForceApplyshort_answermedium
More from Electromagnetic Induction
- Assertion: The mutual inductance between two coils is maximum when the coils are wound on each other. Reason…2024 · asked 3×
- In the process of charging of a capacitor, the current produced between the plates of the capacitor is:2023 · asked 3×
- A vertically held bar magnet is dropped along the axis of a copper ring having a cut as shown in the diagram.…2025 · asked 3×
- The direction of induced current in the loop abc is:2023 · asked 3×
- (i) Define self-inductance of a coil. Derive the expression for the energy required to build up a current I…2025 · asked 3×
- Two coils C 1 and C 2 are placed close to each other. The magnetic flux φ 2 linked with the coil C 2 varies…2023 · asked 3×
- Assertion: Induced emf produced in a coil will be more when the magnetic flux linked with the coil is more.…2026 · asked 3×
- (i) State Lenz's law and explain how this law is a consequence of conservation of energy principle. (ii) A…2025 · asked 3×
CBSE Class 12 Physics past-paper question from the 2023board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.