Ohms law states that V = I (current) x R
Rearranging for I, I = V / R
therefore I = 20 / 4 = 5 Amps
First of all, current goes straight through the resistor, not across it.If the potential difference between the ends of the resistor is 20 volts,and its resistance is 10,000 ohms, then the current through it isI = E/R = 20/10,000 = 0.002 ampere = 2 milliamperes
If there's nothing else between the ends of the resistor and the power supply, then the voltage across the resistor is 24 volts, and the current through it is 2 amperes.
The value of a resistor with 5 volts across it and 20 milliamperes of current flowing through it is 250 ohms. Ohm's Law: E = I R R = E/I
Voltage / Resistance = Current, you do the math
V = (I) x (R) = 2 x 12 = 24 volts
You just stated that the voltage across the resistor is 15 volts, so that's your answer ! If the resistor is connected to a 15-V battery or to the output of a 15-V power supply, then a meter across the resistor is also across the power supply, and reads 15 volts. The current through the resistor is (V/R) = (15/2700) = 5.56 mA. The power dissipated by the resistor (and delivered by the battery) is (V2/R) = (225/2700) = 0.083 watt.
The question is incomplete without the voltage across the resistor. For example: if V (Voltage across 500 ohm resistor) = 5 Volts, then, Current, I = 5/500 Ampere = 0.01 A.
Use Ohm's Law, i.e., V=IR here, V=voltage I=current R=resistance
Use Ohm's Law - in this case, solving for current: I = V/R (current = voltage divided by resistance). Since you are using standard SI units, the answer will be in amperes.
Ohm's Law: Volts = Amps * Ohms That means that you have 45 volts across the resistor. Power = Volts * Amps That means that you 3.375 Watts going through the resistor.Alternative AnswerMultiply the square of the current by the resistance.
Here are some practice questions based on Ohm's Law: If a resistor has a resistance of 10 ohms and a current of 2 amperes flowing through it, what is the voltage across the resistor? A circuit has a voltage of 12 volts applied across a resistor with a resistance of 4 ohms. What is the current flowing through the resistor? If a circuit has a current of 0.5 amperes flowing through a resistor with a resistance of 8 ohms, what is the voltage across the resistor? These questions will help you practice applying Ohm's Law to calculate voltage, current, and resistance in electrical circuits.
Potential difference equals current multiplied by resistance or E = IR therefore the answer to your question is 25 volts