Physics circuit question, PLEASE HELP!!?

Question

3 lamps are connected in parallel to a 12V battery. The resistance is 8 ohm in each lamp
- Calculate the current drawn by each lamp
- The power disipated by each lamp
- The total energy transformed by the 3 lamps in kilowatt hour when operated for 12 hours

Please help me with this, my physics exam is tomorrow and i don't know how to do this. Thank you!

Answer 1

Because the lamps are in parallel, each lamp will see 12V.
I = E/R, so the current draw for each lamp is 12/8 = 1.5 amperes
Power = EI or I^2R. We'll take the easy one P = EI. Voltage is 12, current is 1.5, so power is 18 watts per lamp
There are three lamps, so the total power draw is 54 watts
54 watts times 12 hours = 648 watt-hours = 0.648 KWH

Answer 2

- Calculate the current drawn by each lamp = 1.5 A
We have 3 parallel lamps so lets calculate the total resistance:
1/8 + 1/8 + 1/8 = 3/8 and this means we have 8/3 ohms of resistance.

V = I . R and
V is 12
R is 8/3
so we have 9/2A total current at main circuit. So 3/2A for each lamp.

- The power disipated by each lamp
P=V.I
V is 12Volts
I is 1.5Amperes
so P is 12*1.5=18Watts

- The total energy transformed by the 3 lamps in kilowatt hour when operated for 12 hours
12 hours * 3 lamps * 18 watts = 648watts = 0.648 kW

Answer 3

First, if each lamp has a resistance of 8 ohms when in parallel that will be :
8/3 = 2.66 Ohms Total.
Current = 12v / 2.66 ohms
Current = 4.51 amps Total
Current = 12/8 = 1.5 Amps Each

check: E=IR
E = (1.5)(8)
E = 12 v
// This checks out since voltage is the same for each branch, and each should equal the source in this case.
check :
E = IR
E = (4.51)(2.66)
E = 11.99 V
// This is total and checks out since Total Voltage should be the same at all branches.

//Per Each:
Power = (12)(1.5)
Power = 18 Watts // Each Lamp
Total Power = 54 watts //All Lamps
12(54) =648
.0648 Kwh
rounded : 0.65 KWH

Answer 4

Each lamp will draw 12/8 = 1.5 Ampere
The power consumed by each lamp will be 12 x 1.5 =18W
Total consumption over 12 hours will be
((3 x 18)12)/1000 = 0.648KWH

Answer 5

Use a cutting-edge Divider. the present interior of the two? is 3 * 4/[2+4] = 2A the present interior the 4? is 3 * 2/[2+4] = 1A verify: because they are in parallel, they each and each have an identical voltage V. The voltage interior of the two? coil is then 2*2 = 4Volts and the voltage interior the 4? coil is 4*a million = 4Volts So it tests