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Look on the light bulb for the voltage and the power in watts. Then divide the watts by the voltage and that gives the amps. Some CFL bulbs also state the current as well as the voltage and power, which is because they can have a poor power factor.
Assume the rating of 100W refers to operation on a supply of 117 volts.Power = (voltage) x (current)Current = (power) / (voltage) = 100/117 = 0.855 ampere (rounded)Power = (voltage)2 / (resistance)Resistance = (voltage)2 / (power) = (117)2 / 100 = 136.89 ohms
You know if current is flowing in a bulb circuit because, if there is enough power (voltage times current), the bulb will illuminate. If there is current, but not enough power to illuminate the bulb, you will need to measure the current with an ammeter to see if there is any current.
Power is current times voltage, so a current of 0.5 amperes and a voltage of 220v across a bulb will yield a power of 110 watts.
For the same bulb, there would be no difference if the AVERAGE power is the same. For DC this is easy....Power = V X I. For AC it is much more complicated, for a purely resistive light bulb, Power = Vrms X I. So for AC the voltage is the "root mean square" of the peaks.
The power of a light bulb or appliance depends on its voltage (V) and current (I). The power (P) can be calculated using the formula P = V x I.
Power = Current * Voltage Current = Power / Voltage Current = 60 W / 120 V Curretn = 0.5 A
Look on the light bulb for the voltage and the power in watts. Then divide the watts by the voltage and that gives the amps. Some CFL bulbs also state the current as well as the voltage and power, which is because they can have a poor power factor.
Assume the rating of 100W refers to operation on a supply of 117 volts.Power = (voltage) x (current)Current = (power) / (voltage) = 100/117 = 0.855 ampere (rounded)Power = (voltage)2 / (resistance)Resistance = (voltage)2 / (power) = (117)2 / 100 = 136.89 ohms
You know if current is flowing in a bulb circuit because, if there is enough power (voltage times current), the bulb will illuminate. If there is current, but not enough power to illuminate the bulb, you will need to measure the current with an ammeter to see if there is any current.
You can use Ohm's Law to calculate the current of a light bulb by dividing the voltage across the light bulb by its resistance, which is typically provided on the bulb itself or its packaging. The formula is: Current (I) = Voltage (V) / Resistance (R).
By taking the voltage across the bulb and multiply by the current flow.
Power is current times voltage, so a current of 0.5 amperes and a voltage of 220v across a bulb will yield a power of 110 watts.
there is no voltage and resistance
The current flowing through the 75-watt light bulb connected to a 110-volt wall outlet can be calculated by using the formula: Power = Voltage x Current. Therefore, the current flowing through the light bulb would be approximately 0.68 amps.
there is no voltage and resistance
Since the light bulb is purely resistive (has very little reactance), you can just measure the RMS voltage across the light bulb (usually 120 V) and the RMS current going through the light bulb. Power (P) is:P = VRMS x IRMSwatts