An electrostatic voltmeter reading upto 2500 V is controlled by a spring with a torsion constant of 10 × 10^-6 Nm/rad has full scale deflection of 120°. The capacitance at zero voltage is 20 pF. What is the capacitance when the pointer indicates 2500 V ?

26.7 pF

6.7 pF

14 pF

34 pF

An electrostatic voltmeter reading upto 2500 V is controlled by a spring with a torsion constant of 10 × 10-6 Nm/rad has full scale deflection of 120°. The capacitance at zero voltage is 20 pF. What is the capacitance when the pointer indicates 2500 V ?