Question

A small sphere of mass 1g carries a charge of 6 microcolumb the sphere is suspended by a string in an electric field of 400N/C acting downward calculate tensiob in string

Answer 1

tension in string , T = weight of small sphere + electrostatic force acts on sphere.

weight of small sphere , W = mg

= 1g × 10m/s²

= 10^-3 kg × 10 m/s² = 0.01N

electrostatic force , F = qE

where q is charge on small sphere and E is electric field acting on it.

here q = 6 microcoulombs and E = 400N/C

so, F = 6 × 10^-6 × 400 = 24 × 10^-4

= 0.0024 N

so, tension in string , T = W + F

= 0.01N + 0.0024N

= 0.0124 N

hence tension in string = 0.0124N