For driving a current of 2 A for 6 minutes in a circuit, 1000 J of work is to be done. The e.m.f. of the source in the circuit is

Options

A. 1.38 V
B. 1.68 V
C. 2.03 V
D. 3.10 V

Answer

A

Explanation

If i is the current in a wire then the charge flowing through the wire in t sec is
`q=it=2xx6xx60=720 C`
The work done in taking q coulomb (720 C) of charge from one end of wire to other end under a potential difference of V volt (in this case emf) is
W = V q
`rArr " " V=(W)/(q)=(1000)/(720)=1.38 V`