Question

The potential difference between the terminals of an electric heater is 75V when it draws current of 5A from thesource.What current will the heater draw if the potential difference is increased to 150V

Answer 1

by ohms law v=ri
so 75=5*r
r=15ohm hence it's resistance is 15ohm and it is constant now for new set up 150=i*25=6A
so it's current is 6 ampere

Answer 2

Given :

Potential difference of the heater (V) = 75 V

Current (I) = 5 A

To Find :

What current will the heater draw if the potential difference is increased to 150V.

Solution :

As per Ohm's Law,

  Potential Difference (V) = Current (I) × Resistance (R)

or, Resistance (R)              = $\frac{V}{I}$

or, Resistance (R)              = $\frac{75}{5}$

∴   Resistance (R)              = 15 ohm

Now,

Current when the potential difference is increased to 150V can be given as -

Current (I') = $\frac{150}{15}$

                 = 10 A

Therefore, the current when the potential difference is increased to 150V is 10 A.