Question

An electric iron of resistance 20 ohm takes a current of 50 mA. Calculate the heat developed in 30 sec.

Answer 1

R=20 ohm.
I = 50 mA= 0.05 A
t=30 sec
H=I^2Rt
H=0.05*0.05*20*30
H=1.5 Joules.
Heat developed is 1.5 Joules.

Hope it helps u!!
Please mark it as brainliest!!

Answer 2

Answer:

Given :

• Resistance =30ohm

•current =4 A

• Time=50seconds

To Find :

• Heat developed in 50 seconds=?

Solution :

The amount of heat (H) produced is given by joules law of heating as H=VIT

where, R=30ohm

current ,I=4A

Time, T=50seconds

$\\ \implies \sf \: voltage = current \times resistance \: \\ \\ \implies \sf \: voltage = 5 \times 20 \\ \\ \implies \boxed{ \sf{voltage = 100 \: volt}}$

$\\ \implies\sf{H=VIT}$

$\\ \implies\sf{H=100 \times 4 \times 50}$

$\\ \implies\sf{H=2\times 10^{4}}$

$\\ \implies\boxed{\sf{Heat(H)=2 \times 10^{4}}}$

Therefore, the amount of heat developed in

the electric iron is $\rm{2 \times 10^{4}}$

Additional information :

Ohm's Law : According to this law, applied voltage is directly proportional to the resistance.

The unit of resistance is ohm

$\red\bigstar\boxed{\sf{Applied \: voltage(V) =IR}}$