Power, P, is current, I, times voltage, E. (P = IE)
Not knowing one of voltage, E, or current, I, you can apply ohm's law ...
E = IR or I = E/R
... and come up with variations ...
P = I2R
P = E2/R
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).
P = I^2 x R] P = 0.2^2 x 100 P = 4 W
Take your pick:P = V x I (Power = Voltage x Current)or:P = V2 / R (Power = Voltage2 / Resistance)or:P = I2 *R (Power = Current2 x Resistance)(the last two equations come from combining the ohms law equation R=V/I with the power equation P=VxI)In the question above you have resistance and current therefore:P = I2 *R = 0.0052 x 8.2k = 0.0052 x 8200 = 0.205W = 205mW
Power dissipated is always Volts times Amps. W= V*I because of ohm's law, V=I*R, you can substitute either the voltage or amperage with the other value; W= V^2/R or W= I^2*R.
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.
The power dissipated by a resistance 'R' carrying a current 'I' is [ I2R ]. The power is dissipated as heat, and you can see from [ I2R ] that for a given current, it's directly proportional to 'R'.
That's not always the case. One formula for power dissipated is:P = IRSo, a higher resistance means that more power is dissipated - if the current is the same. The reason for this is precisely that resistance is related to the conversion of electrical energy into heat.However, if you put a higher resistance across a specific voltage, you'll get less power dissipation, not more, since less current will flow at a higher resistance.
Power = I2 R = (0.02)2 x (1,000) = 0.4 watt
Power dissipated in a resistance = E2/R = (100)2/100 = 100 watts.
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).
7.0w/4 = 1.75w
In a toaster, the house current from the outlet passes through a wire with some resistance. Household electricity is supplied at a nominal 117 volts AC. If 'R' is the resistance of the wire in the toaster, then the power (heat) dissipated by the wire is E2/R = (117)2/R watts of heat. Notice that as long as the voltage remains constant, MORE resistive heat is dissipated from a SMALLER resistance.
I = 2A R = 1000Ω Power Dissipated P = I2R = (2A)2(1000Ω) = 4000W Voltage across resistor V = IR = (2A)(1000Ω) = 2000V
The formula P = I^2R relates power (P), current (I), and resistance (R), indicating the power dissipated in a resistor. On the other hand, the formula P = V^2/R relates power (P), voltage (V), and resistance (R), representing the power dissipated across a resistor. The former formula deals with power in terms of current, while the latter formula expresses power in terms of voltage.
The power P dissipated by a resistor will leave the resistor in the form of thermal energy (heat). It will get hot due to the fact that the material it is made of opposes current flow, and when current is forced through it by a voltage source, it gets hot in response. Resistance R could be thought of as "electrical friction" in many cases. Resistance is measured in ohms, voltage V in volts and current I in amperes (amps). The power in watts dissipated by a resistor with the value R will be the square of the current through it times its resistance. P=I2R The power in watts dissipated by a resistor with the value R will be the square of the voltage drop across it divided by its resistance. P=V2/R Because E means energy we take V for voltage. The power in watts dissipated by a resistor with the value R will be the voltage drop across it times the current flow through it. P=IV All three statements are true, and they all say the same thing. The mathematician might say that the variable P is being expressed in terms of the variables I, V and R. As all the statements are true, it can be said that P=I2R=V2/R=IV.
P = I^2 x R] P = 0.2^2 x 100 P = 4 W
In a DC circuit, the power dissipated by a resistance is (voltage across it)2 divided by 'R'.P = E2/R = (14.1)2 / 142 = 198.81/142 = 1.4 watts(rounded)