[填空题]
A parallel-plate capacitor with plate area3j(wi ye,8ibmk:cq /w w33lm edgz,;io5 tpjmgb4ox 5k5x-u2 w ex,7y $2.0cm^2$ and air-gap separation 0.50 mm is connected to a 12-V battery, and fully charged. The battery is then disconnected.
(a) What is the charge on the capacitor? $ \times10^{ -11}\,C$
(b) The plates are now pulled to a separation of 0.75 mm. What is the charge on the capacitor now? $ \times10^{ -11}\,C$
(c) What is the potential difference across the plates now? V
(d) How much work was required to pull the plates to their new separation? $ \times10^{-10 }\,J$
