Question

a 15 ohm resistor and a 25 ohm resistor are connected in parallel to a 60 volt battery. what is the power used by each device

Answer 1

25 ohm resistor

E = I * R                    General formula

• E = 60 volts    Givens
• R = 25 ohms

60 = I * 25                Divide by 25

60/25 = I*25/25      

2.4 = I

P = E * I

E = 60 volts

I = 2.4 amps

P = 60*2.4

P = 144 watts.                 Answer: 25 ohm Resistor

==============  

15 Ohm Resistor

E = I R

• E = 60 volts
• R = 15 ohms

I = ??

60 = I * 15                Substitute

60/15= I * 15/15       Divide by 15

I = 4

P = E * I

• E = 60
• I = 4

P = 60 * 4

P = 240 Watts.               Answer: 15 ohm resistor