The relationship between frequency and $xc$ is $q,(5$pts$)$

The relationship between frequency and XI is $q,(5$pts$)$

For a voltage sine wave, the rate of change of voltage is maximum at $q,(5$pts$)$

a$)90$ and $180$

b$)90$ and $270$

c$)0$ and $180$

d$)0$ and $270$