Solving Ohm's Law Homework Questions

In summary: I'm not sure what you are asking. Can you please clarify what you are trying to do?In summary, current through a device (in this case an electrical pump) is proportional to the voltage applied and the resistance of the device.
  • #1
WMM
17
0

Homework Statement


1. A nine volt battery supplies power to a cordless curling iron with a resistance of 18 ohms. How much current is flowing through the curling iron?
2. A 110 volt wall outlet supplies power to a strobe light with a resistance of 2200 ohms. How much current is flowing through the strobe light?
3. A CD player with a resistance of 40 ohms has a current of 0.1 amps flowing through it. Calculate how many volts supply the CD player?
4. A small electrical pump is labeled with a rating of 3 amps and a resistance of 40 ohms. What voltage was it meant to run at?
5. A lamp is plugged into the wall outlet, which is providing 110 volts. An ammeter attached to the lamp shows 2 amps flowing through the circuit. How many ohms of resistance is the lamp providing?

The Attempt at a Solution

Don't know where to start.
 
Physics news on Phys.org
  • #2
Start with question 1 and apply Ohm's Law as the title of your post suggests.
 
  • #3
As you stated in the title, Ohm's Law. Simply plug what you know into Ohm's Law and solve for the unknown value.
 
  • #4
p21bass said:
As you stated in the title, Ohm's Law. Simply plug what you know into Ohm's Law and solve for the unknown value.

I'm lot though I know about it but they tell you what Ohms law is and it confuses me.

f9ae53a99f2b2b6a74146fb04fb3ff73.png
 
  • #5
WMM said:
I'm lot though I know about it but they tell you what Ohms law is and it confuses me.

f9ae53a99f2b2b6a74146fb04fb3ff73.png
What confuses you? Can you state in plain English and without equations what Ohm's Law says?
 
  • #6
What do I use to figure out the problem?
The only thing it gives me is 18ohms for the first one.

Just completely lost and when I try to read about the Ohms law none of it makes sense.
 
  • #7
Does V = I R make more sense? Some times Ohm's Law is written in this form.
 
  • #8
it is very simple..

the current equals the voltage divided by the resistance...
and in first problem, the voltage equals 9 V (9V battery) and the resistance is 18 ohms...

so try to figure it out...
 
  • #9
So the current is 2? What is that measured in, AMPS?
 
  • #10
WMM said:
So the current is 2? What is that measured in, AMPS?
Look it up.
 
  • #11
no... voltage divided by the resistance = 9 / 18 = 1/2...

and yes, current is measured in amps
 
  • #12
1. Since V and R are known, solve for I which is current by dividing both sides of the equation by R.

V = I x R
R R

I = V
R

I = 9
18

I = 0.5 Amps

2. Current = 0.05 Amps

I managed to get the first 2 done.

No I'm stuck on the last 3.
 
  • #13
uhh...it doesn't seem like you are even trying.. doesn't physics require you to have some knowledge of algebra at least...?

you already have the equation right there: V = I x R
all the problems give you 2 of the unknown variables.. why can't you solve for the one remaining variable?
 

1. What is Ohm's Law?

Ohm's Law is a fundamental law in physics that describes the relationship between voltage, current, and resistance in an electrical circuit. It states that the current through a conductor between two points is directly proportional to the voltage across the two points, and inversely proportional to the resistance between them.

2. How do I solve Ohm's Law problems?

To solve Ohm's Law problems, you will need to use the formula V = IR, where V is voltage, I is current, and R is resistance. You will need to know at least two of these values to solve for the third. Simply plug in the known values and solve for the unknown using basic algebra.

3. What are the units of measurement for voltage, current, and resistance?

Voltage is measured in volts (V), current is measured in amperes (A), and resistance is measured in ohms (Ω). In some cases, smaller units such as millivolts (mV), milliamperes (mA), and kilohms (kΩ) may also be used.

4. Can Ohm's Law be applied to all electrical circuits?

Yes, Ohm's Law can be applied to all electrical circuits, as long as the circuit is a simple, linear circuit with a constant resistance. It may not apply to more complex circuits with non-linear components, such as diodes or transistors.

5. What are some real-life applications of Ohm's Law?

Ohm's Law has many real-life applications, such as in designing and analyzing electrical circuits, calculating the power consumption of household appliances, and determining the appropriate gauge of wire to use for different applications. It is also used in the design and analysis of electronic devices, such as computers and cell phones.

Similar threads

Ohm's Law confusion -- How to handle an incandescent bulb?
    • Introductory Physics Homework Help
Replies
7
Views
677
Ohm's law and Kirchoff — What am I missing?
    • Introductory Physics Homework Help
Replies
4
Views
1K
I Does Ohm's Law work for Light Bulbs?
    • Classical Physics
2
Replies
57
Views
7K
Circuit Problem -- Combining 4 resistors to make 95 Ohms
    • Introductory Physics Homework Help
Replies
10
Views
2K
Connection between V vs I graphs and Ohm's Law
    • Introductory Physics Homework Help
Replies
7
Views
5K
Lab Experiment: Estimate the error in these measurements of Ohm's law
    • Introductory Physics Homework Help
Replies
2
Views
1K
I Propagation of Errors, Ohm's Law
    • Classical Physics
Replies
6
Views
2K
Resistive dissipation and Ohm's law
    • Introductory Physics Homework Help
Replies
5
Views
2K
Ohm's Law Validity: Does it Change with Heat?
    • Introductory Physics Homework Help
Replies
1
Views
2K
I Resistance and specific resistance relationships
    • Electromagnetism
Replies
16
Views
643

Hot Threads

Recent Insights

Back
Top