how many bulbs of resistance 6 ohm should be joined in parallel to draw a current of 2 amperes from a battery of 3 volts.?
Solution:
Suppose n resistances of 6 ohm are connected in parallel and the resultant resistance=R
Then,
1/R=n/6=>R=6/n
Now Current I=2 A,Voltage V=3 volts
By ohm's law V=IR
3=2x6/n
n=4
Hence 4 bulbs are connected in parallel.