Question

A $1.0\, m$ long metallic rod is rotated with an angular frequency of $400 \,rad /s$ about an axis normal to the rod passing through its one end. A constant and uniform magnetic field of $0.5\, T$ parallel to the axis exists everywhere. The emf developed across the ends of the rod is

• A. 50 V
• B. 100 V
• C. 150 V
• D. zero

Answer 1

Answer: (B)

100 V

Answer 2

The correct option is(B): 100 V.

The emf developed across the ends of the rod
$e=\frac{1}{2} B l^{2} \omega$
$=\frac{1}{2} \times 0.5 \times(1)^{2} \times 400$
$=100\, V$