Question

if a current flow from an electric wire for 20 min .if the potential difference and resistance of wire are 7 volt ad 5 ohm then find the heat produced by this .please answer elaborately.

Answer 1

see we know that V=IR then for I = V÷R
so I=1.4 ampere
now to find heat we know that,
H =I×I×R×t ( where I is current and R is resistance and T is time
H= 1.4×1.4×5×20×60=11760joule

Answer 2

V = 7 volt
t = 20min = 20 × 60s = 1200s
R = 5 ohm
The thermal energy generated = V²T / R
= 7 × 7/5 × 1200 J = 49 × 240 J
= 11760 J = 11760 / 4.2 cal = 2800 cal