# Class 12 Physics Electrostatic Potential and Capacitance: NCERT Solutions for Question 7

This page focuses on the detailed Electrostatic Potential and Capacitance question answers for Class 12 Physics Electrostatic Potential and Capacitance, addressing the question: 'Three capacitors of capacitances 2 pF, 3 pF and 4 pF are connected in parallel. (a) What is the total capacitance of the combination? (b) Determine the charge on each capacitor if the combination is connected to a 100 V supply.'. The solution provides a thorough breakdown of the question, highlighting key concepts and approaches to arrive at the correct answer. This easy-to-understand explanation will help students develop better problem-solving skills, reinforcing their understanding of the chapter and aiding in exam preparation.
Question 7

## Three capacitors of capacitances 2 pF, 3 pF and 4 pF are connected in parallel.(a) What is the total capacitance of the combination?(b) Determine the charge on each capacitor if the combination is connected to a 100 V supply.

(a) Capacitances of the given capacitors are

C1 = 2 pF,

C2 = 3 pF,

C3 = 4 pF,

For the parallel combination of the capacitors, equivalent capacitoris C' given by the algebraic sum,

C'=2 +3 + 4= 9 pF

Therefore, total capacitance of the combination is 9 pF.

(b) Supply voltage, V = 100 V

The voltage through all the three capacitors is same = V = 100 V

Charge on a capacitor of capacitance C and potential difference V is given by the relation,

q = VC … (i)

For C = 2 pF,

Charge= VC = 100 x 2 = 200 pC = 2 x 10-10 C

For C = 3 pF,

Charge = VC = 100 x 3 = 300 pC = 3 x 10-10 C

For C = 4 pF

Charge = VC = 100 x 4 = 400 pC = 4 x 10-10 C