Question

An electric heater coils are broken into two parts of the same length and only one of them is used in the heater. The ratio of the heat produced by this half coil to that the initial coil is

Answer 1

Heat produces is given as

H = i²Rt

where

R = ρl/A

So,

H = i²(ρl/A)t

now if l' = l/2

then

H' = 1/2[ i²(ρl/A)t] = H/2

thus, the heat produced would be halved.