Rituraj Tiwari
Last Activity: 4 Years ago
Let’s apply the capacitor's equation:
Q = C . V
▶Where Q is the charge, C the capacitance, and V the voltage.
Q0 = C0 . V0, where C0 is 100pF and V0 is 100V
▶When we connect the capacitors in parallel, we equal the voltage on the two, therefore:
V = Q / C ==> Q0′/C0 = Q1/C1
▶Where Q0' is the charge on the 100pF capacitor after connecting the other one, and Q1 and C1 the homologous.
We also know that the total charge is conserved, so:
Q0 = Q0' + Q1
And we know that Q0' = C0 . V1, where V1 = 30V
♦We have three equations and three unknowns Q0', Q1, and C1. You can go ahead and solve it and then punch in the values of the constants.