Question

Consider the situation given in the figure. The wire AB is slid on the fixed rails with a constant velocity. If the wire AB is replaced by a semicircular wire, the magnitude of the induced current will

• A. decrease
• B. increases
• C. increase or decrease depending on whether the semicircle bulges towards the resistance or away from it
• D. remain same

Answer 1

The correct option is D

remain same

The explanation for the correct option:

In the case of option D,

1. The current is created in a wire when the magnetic field changes are called induced current.
2. The current created in a generator typically requires quickly rotating a wire coil together in a magnetic field, which would be an instance of induced current.
3. The induced emf is written as $e=l\left(\stackrel{\rightharpoonup }{V}\times \stackrel{\rightharpoonup }{B}\right)$. Here $I$ is current, $V$ is voltage and $B$ is magnetic field.
4. It can also be written as $e=IVB\sin \theta$.
5. The induced current can written as $I=\frac{e}{R}$.
6. If the straight wire is replaced by a semicircular wire, resistance R remains unchanged. Hence, currently remains the same.

Hence, Option(D) is correct.