Question

14. A 5-metre long copper wire costs Rs 12.60. Find the cost of 37 metres of such
wire.

​

Answer 1

Answer:

Here,

Length of the wire, l=10m

Speed, V=5m/s

Earth's magnetic field , B=0.30×10

−4

Wbm

−2

We know,

Instantaneous value of e.m.f induced in the wire ,

e=BIV

=0.30×10

−4

×10×5.0

=1.5×10

−3

V

Answer 2

5m cost = 12.60

then 1m cost = 12.60÷5= 2.52

37m cost = 37×2.52= 93.24