Q136 / 160 · AP EAMCET 2020 (22 Sep Shift 1) · Physics
Consider the situation shown in the figure. The wire $A B$ is sliding on the fixed rails with a constant velocity. If the wire $A B$ is replaced by semicircular wire, the magnitude of the induced current will
- Aincrease
- Correct answerBremain the same
- Cdecrease
- Dincrease or decrease depending whether the semicircle bulges towards the resistance or away from it
Solution
Magnitude of induced current in the wire $A B$ is given as
$$
I=\frac{B v l \sin \theta}{R}
$$
Here,
$$
\begin{aligned}
& \theta=90^{\circ} \\
& I=\frac{B v l}{R}
\end{aligned}
$$
$$
\therefore
$$
When wire $A B$ is replaced by semicircular wire, then neither $l$ nor $\theta$ are changed. $B, v$ and $R$ are already constant. Hence, induced current will remains same.
Hence, the correct answer is option: 'B'.