Question

If the current flowing through an electric heater increases from 6 to 12 amp while the voltage remains the same, the heat produced by the heater will be
a. reduced one-half.
c. two times the original heat.
b. unchanged.
d. four times the original heat.

Answer 1

Q=l^2 times R times t
Where Q - heat, I -current, R - resistance and t is time

If you increase I twice (and it's squared), than Q gonna went up 4 times (2 squared).

Choose last

Answer 2

Explanation:

It is given that,

Current, $I_1=6\ A$

Heat produced, $H_1=I_1^2Rt$............(1)      

Where

R is the resistance

t is the time taken

So, $H_1=36Rt$

Current, $I_2=12\ A$

Heat produced, $H_1=I_2^2Rt$      

So, $H_2=144Rt$.............(2)

From equation (1) and (2), it is clear that

$H_2=4\times H_1$

So, If the current flowing through an electric heater increases from 6 to 12 amp while the voltage remains the same, the heat produced by the heater will be four times the original heat.