In the A. C. circuit shown, keeping 'K' pressed, if an iron rod is inserted into the coil, the bulb in the circuit

Options

A. gets damaged
B. glows less brightly
C. glows with same brightness (as before the rod is inserted)
D. glows more brightly

Answer

B

Explanation

As the iron rod is inserted, the magnetic field inside the coil magnetizes the iron increasing the magnetic field inside it. Hence, the inductance of the coil increases. As a result, a larger fraction of the applied ac voltage appears across the inductor, leaving less voltage across the bulb. Therefore, the bulb glows less brightly,