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When a 3 ohm resistor draws a current of 4 A when hooked up to a battery of unknown voltage what is the battery's voltage and what is the power dissipated by the resistor?
Wiki User
∙ 14y ago
Voltage can be calculated using Ohm's Law:
Voltage = Current (A) x Resistance (Ω)
Voltage = 4A x 3Ω = 12 Volts
Therefore, the battery is a 12 Volts.
The power dissipated is Voltage x Current
Power = 4A x 12V = 48 Watts
Wiki User
∙ 14y ago
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What is the power dissipated by a resistor with a current of 0.02 A adn a resistance of 1000 ohms?
Power dissipated = I2R 0.022 x 1000 = 0.4 watts
A red resistor draws more current than a blue resistor when they are connected to the same battery which resistor has the lower resistance?
The voltage of a battery goes as the current times the resistance (V=IR). Because the voltage is being held constant, the resistor that draws the most current will have the lower resistance.
Voltage drop of 15 Volts across 2.7 killo ohm resistor?
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.
When a resistor is connected in parallel what happens to the size of current form the battery?
When a resistor is added the current goes down, that is expressed in the equation current= voltage/ resistance
What is the current running through a resistor of 9 ohms with volts of 90?
I = E / RIf the voltage across the resistor is 90 volts, and the resistance of the resistoris 9 ohms, then the current through the resistor is90/9 = 10 Amperes.Don't try this at home!The power dissipated by the resistor is E2/R = (90)2/9 = 900 watts. That's comparable to the power (heat) dissipated by a small toaster. A common composition resistor will get hot and possibly explode if it's asked to dissipate that kind of power.
2 resistors unequal value are in parallel. Would the power dissipated by the resistor with larger ohmic value be greater than the power dissipated by the resistor of lesser value?
No, because the power dissipated in a resistor is proportional to the square of the current through the resistor but only directly proportional to the resistance of the resistor (I^2 * R) and the current through the lower value resistor will be higher than the current through the higher value resistor, the lower value resistor will usually dissipate more power.
What power is dissipated by an 8.2 k resistor if a current of 0.005 amps pass's through the resistor?
.205 watts or 205 mw
What is the power dissipated by a resistor with a current of 0.02 A adn a resistance of 1000 ohms?
Power dissipated = I2R 0.022 x 1000 = 0.4 watts
How do you measure current without an amp meter?
Depends on the current. Put a resistor in-line with the current, then measure the voltage across the resistor. V=RI. So, divide the measured voltage by resistor value. Be careful with the size of the resistor, as Power dissipated in a resistor is R*I^2 or V^2/2. So, a 1-Amp current into a 1 Ohm resistor will result in a 1Watt power dissipated in the resistor. If it's too small, it'll burn. Also, notice that if you do that, you haven't measured the current in the original circuit. You've measured the current when an extra resistor is installed in the original circuit, and that's different.
How Determine the power dissipated by the resistor?
Power dissipated by the resistor = I^2 * R or V^2 / R, where R = its resistance value, I = the current in the resistor, and V = the voltage drop across the two terminals of the resistor. You need to measure or find the information of either I (using an ammeter) or V (a voltmeter).
What is the power dissipated by a resistor with a current of 2 amps and a resistance of 1000 ohms?
I = 2A R = 1000Ω Power Dissipated P = I2R = (2A)2(1000Ω) = 4000W Voltage across resistor V = IR = (2A)(1000Ω) = 2000V
What is the power dissipated a resistor with a current of 0.02 amps and a resistance of 1000 ohms?
P = I^2 x R] P = 0.2^2 x 100 P = 4 W
What is series connection?
You have two resistors, each with resistance of 12Ω, and a 12-volt battery. 1). The resistors are in series across the battery. ..... A. voltage across each resistor ..... B. current through each resistor ..... C. power dissipated by each resistor ..... D. total power delivered by the battery 2). The resistors are in parallel across the battery. ..... A. voltage across each resistor ..... B. current through each resistor ..... C. power dissipated by each resistor ..... D. total power delivered by the battery ============================================ 1). ... A. 6 volts ... B. 0.5 Amp ... C. 3 watts ... D. 6 watts 2). ... A. 12 volts ... B. 1 Amp ... C. 12 watts ... D. 24 watts
A red resistor draws more current than a blue resistor when they are connected to the same battery which resistor has the lower resistance?
The voltage of a battery goes as the current times the resistance (V=IR). Because the voltage is being held constant, the resistor that draws the most current will have the lower resistance.
Voltage drop of 15 Volts across 2.7 killo ohm resistor?
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.
Can you charge an 8 volt battery with a 12 volt charger?
No, it would overcharge and ruin the battery. #2 You can do it by using a series resistor to limit the current. The resistance needed is equal to the voltage drop divided by the charging current. The voltage drop is 4, and the charging current is one tenth the battery capacity, for example for a 2000 mAh battery the charging current is 200 mA. So the resistance needed is 4/0.2 or 20 ohms. The power dissipated in the resistor is 4 x 0.2, or 0.8 watts, so you need a 20 ohm 1-watt resistor. The battery should be charged for at least 10 hours if fully discharged, or until it becomes slightly warm to the touch. Do NOT let it overheat.
When a resistor is connected in parallel what happens to the size of current form the battery?
When a resistor is added the current goes down, that is expressed in the equation current= voltage/ resistance
