# physics

posted by .

The operating potential difference of a light bulb is 120 V. The power rating of the bulb is 105 W. Find the current in the bulb and the bulb's resistance.
Current
1 A
Resistance
2

I got 0.916 for A
and 115 for B but they are wrong

• physics -

P=I•U ,
I =P/U =105/120 =0.875 A
P =I²•R,
R=P/I² =105/120²=7.3•10^-3 Ω

• physics -

the second answer is supposed to be in the hundreds

• physics -

7.3•10^-3 = 0.0073

## Respond to this Question

 First Name School Subject Your Answer

## Similar Questions

1. ### Physics

1)Bulb P is rated 60 W, 110 V and bulb Q is rated 100 W, 110 V. Which of the bulbs has the higher resistance?
2. ### physics

A light bulb, after it has reached its operation temperature, is connected across a potential difference of 120V while 0.5A of current passses through it. What is the resistance of the light bulb?
3. ### College Physics

The power dissipated by a light bulb increases by 50 W when the potential difference applied across the light bulb increases from 50 V to 100 V. Find the resistance of the light bulb.
4. ### PHYSICS

Two bulbs are connected in parallel across a source of emf EMF = 10.0V with a negligible internal resistance. One bulb has a resistance of 3.0 Omega , and the other is 2.5 Omega . A resistor R is connected in the circuit in series …
5. ### physics

Two bulbs are connected in parallel across a source of emf EMF = 10.0V with a negligible internal resistance. One bulb has a resistance of 3.0 Omega , and the other is 2.5 Omega . A resistor R is connected in the circuit in series …
6. ### physics

You are in the lab with a 10 V battery. You have a 10 W light bulb and you want to put 1/2 A of current through the light bulb and 5 V across the light bulb. This will allow the light bulb to have a brightness proportional to 2.5 W. …
7. ### college physics

You are in the lab with a 10 V battery. You have a 10 W light bulb and you want to put 0.75 A of current through the light bulb and 7.5 V across the light bulb. This will allow the light bulb to have a brightness proportional to 5.625 …
8. ### physics

(a) What is the hot resistance of a 24 W light bulb that runs on 120 V AC?
9. ### physics

(a) What is the hot resistance of a 24 W light bulb that runs on 120 V AC?
10. ### Physics-Answer Check

You have an LED bulb that uses 4 watts of power and gives an output of 170 lumens. The operating voltage is 120 volts. Using this data, find the following. 1. What is the current that the LED bulb uses?

More Similar Questions