Problem

A pendulum bob of mass

m

carrying a charge

q

is at rest with its string making an angle

\theta

with the vertical in a uniform horizontal electric field

E

. The tension in the string is (a)

\frac{mg}{\sin \theta}

(b)

mg

(c)

\frac{qE}{\sin \theta}

(d)

\frac{qE}{\cos \theta}