An alternating current having peak value 14 A is used to heat a metal wire. To produce the same heating effect, a constant current i can be used where i is

1.  14 A

2.  about 20 A

3.  7 A

4.  about 10 A

An AC source rated 100 V (rms) supplies a current of 10 A (rms) to a circuit. The average power delivered by the source 
(a) must be 1000 W.
(b) may be 1000 W.
(c) may be greater than 1000 W.
(d) may be less than 1000 W.
Choose the correct option:
1. (a) only
2. (b), (c)
3. (b), (d)
4. (a), (d)