A capacitor is connected to a 9 V battery and acquires a charge Q. What is the charge on the capacitor if it is connected instead to an 18 V battery? A capacitor is connected to a 9 V battery and acquires a charge Q. What is the charge on the capacitor if it is connected instead to an 18 V battery? 2Q 4Q Q Q/2 Request Answer Part B - Potential difference in a parallel-plate capacitor

2Q

Explanation:

The expression for the electric charge stored in a capacitor is given as,

Q = CV Equation 1

Where Q = Electric charge, C = Capacitance of the capacitor, V = Potential difference applied across the plates of the capacitor.

make C the subject of the equation

C = Q/V Equation 2

Given: Q = Q, V = 9 V

Substitute into equation 2

C = Q/9 F.

If it is connected to an 18 V battery instead,

Q = CV

Given: C = Q/9 F, V = 18 V

Q = (Q/9)(18)

Q = 2Q.

Hence the charge on the capacitor = 2Q.