Solving Variable Resistance Circuit: Ohm's Law

In summary, the question is about finding the resistance needed for a circuit with a variable resistance of 100 ohms and a voltage of 12V or 6.2V. The only equation available to solve this problem is Ohm's Law (V=IR), but the person has not been able to get the correct answer. They are wondering if there is something they are missing or if they are being asked to solve for two unknowns. A possible solution is given but the person is not entirely confident in it. A diagram was requested but one is not available at this time.
  • #1
Warrzie
3
0

Homework Statement


"A circuit has a variable resistance (total 100 ohms) across which is a voltage drop of 12 V supplied by a battery. What must be its resistance if the voltage is to be A) 12V and B) 6.2V?"

Homework Equations


V=IR


The Attempt at a Solution


We haven't learned anything besides Ohm's Law for these equations, so I tried plugging in different values to try and dial in the answers, but it didn't work. Is there something I'm missing or am I being asked to solve for two unknowns? Hints appreciated.
 
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  • #2
Is that all you have? Diagram? I am assuming total resistance is 100 ohms so for 12 v you have 8.5 amps. Then for 12V, you need a resistance of 12/8.5 but I don't trust this answer. If its a serial pair of resistors where Rx and Ry are 100 ohms and you are being asked the voltage drop across Rx, i think the above is good.
 
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  • #3
 
  • #4
drawing a blank on the diagram, literally
 

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.

What is a variable resistance circuit?

A variable resistance circuit is an electrical circuit in which the resistance can be changed or varied. It typically consists of a resistor that can be adjusted to different values, allowing for different amounts of current to flow through the circuit.

How do you solve a variable resistance circuit using Ohm's Law?

To solve a variable resistance circuit using Ohm's Law, you need to know the values of the voltage, current, and resistance in the circuit. You can then use the formula V = IR, where V is voltage, I is current, and R is resistance, to calculate any one of these values if you know the other two.

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 the metric system, these units can also be expressed as kilovolts (kV), milliamperes (mA), and kiloohms (kΩ).

What are some common applications of solving variable resistance circuits using Ohm's Law?

Solving variable resistance circuits using Ohm's Law is essential in many areas of science and technology, including electronics, telecommunications, and power systems. It is also used in various household devices such as light bulbs, heaters, and appliances.

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