Question

A pith ball of mass 0.2g is hung by insulated thread between the plates of a capacitor of separation 8cm . Find the potential difference between the plates to cause the thread to incline at an angle 15° with the vertical , if the charge in the pith ball is equal to 10^-7

Answer 1

Answer:

Hope it helps you

Explanation:

Please see the attached solution

Answer 2

V = 6.15×10³ volts

Explanation:

On balancing horizontal and vertical forces, we get:

Tcos θ = mg

Tsin θ = QE where Q is the charge and E is the electric field.

Dividing the equations we get:

T sin θ / T cos θ = QE / mg

Tan θ = (Q V/d) / mg

Tan θ  = QV/dmg

So Potential difference V = dmg / Q tan θ  

= ( 8 * 10^-2 * 0.2 * 10^-3 * 10 ) / ( 10^-7 tan 15)

= 1.6 * 10³ / tan 15

=  1.6 * 10³ / 0.26

= 6.15×10³ volts.