Alternating Current

Question 1

voltage in a AC circuit

Answer 1

V=Vm Sin(wt)

Question 2

Current in a AC Circuit

Answer 2

I=Im sin(wt)

Question 3

phase difference between current and voltage in purely resistive circuit

Answer 3

no phase difference

Question 4

average value of AC in one cycle is

Answer 4

zero

Question 5

The average value of a.c. over one half cycle is

Answer 5

0.637 times the peak value
0.637 * i

Question 6

I(rms)

Answer 6

I(rms)= i/root 2

Question 7

V(rms)

Answer 7

V(rms)=V/root 2

Question 8

average power

Answer 8

<p>=I(mrs) ^2 * R
</p>

Question 9

phase difference between current and voltage in purely inductive circuit

Answer 9

current lags by pi/2 or one quarter
i=i(m) sin( wt- [pi/2] )
v=v(m) sin(wt)

Question 10

current in inductive circuit

Answer 10

i=Vm/wL sin(wt)
where
wL–>inductive reactance(denoted by XL)

Question 11

Instantaneous power supplied to the inductor

Answer 11

PL= -1/2VmIm*sin(2wt)

Question 12

average power in inductive circuit over a complete cycle is

Answer 12

zero

Question 13

phase difference between current and voltage in purely capacitive circuit

Answer 13

current leads by pi/2
i=im sin(wt+pi/2)
v=vm sin(wt)

Question 14

current in capacitive circuit

Answer 14

i = Comegavm* sin(omega*t + pi/2)

Question 15

capacitive reactant

Answer 15

Xc=1/WC

Question 16

Instantaneous power supplied to the capacitor

Answer 16

1/2VmIm*sin(2wt)

Question 17

average power in capacitive circuit over a complete cycle is

Answer 17

zero