A coil of electric heater with a resistance of is immersed in of oil, current of magnitude is passed through the coil, after seconds of heating, the coil raises the temperature of oil by . What is the specific capacity (in J/kgK) of the c
Resistance of coil ,R = 20 ohm
mass of oil , M = 1 kg
current passing through it , I = 5A
time taken , t = 30 sec
you know , heat dissipates , H = I²Rt
= 5² × 20 × 30 = 25 × 600 J
we also know, Q = Ms ?T
here M is the mass of water , s is specific heat capacity. and ?T is the temperature.
so, Q = 1 × s× 20
now, Q = H
1 × s × 20 = 25 × 600
s = 750 J/kgK