Answers

2014-01-08T20:18:14+05:30
The coil tries to respond to the varying AC. If the frequency is low, the meter would wind up swing back and forth at that frequency. Higher frequencies, the meter cannot respond, so it sits in the middle, reading the average value, zero. 

PS, you get more answers if you define your abbreviations. Or better, don't use them. 
1 5 1