The voltage drop across a 500watt electric heater having resistance of 5 ohm is:

Question

50volt,250volt,2500volt,100volt

Answer 1

From Ohm's law you know that V=IR and P=VI

Step 1: combine the 2 equations where I=V/R

that will give you V^2/R=P

Step 2: solve for V

V^2=R*P

V=squareroot(R*P)

Step 3 fill in the numbers

V=Squareroot(500*5)

squareroot(2500)=50V drop.

My advice given by a professor, solve all your equations with variables then plug the numbers in at the end. This way you see where your numbers come from and help you understand the equations better.