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The simple answer is you can't. However, there may be other ways to calculate it.
If you know the voltage rating (E) and wattage rating (P, for Power) of the item, such as a light bulb, you can calculate the expected current (I) of the item using the formula P = IxE and then substituting the current into the formula E = IxR to calculate the resistance (R). Simple high school algebra will solve these equations.
If an item is not rated in watts it may be rated in volt-amps (VA) which can be used in the same formulas in the place of P.
Some items, such as flourescent lamps, motors, electronics, anything with a ballast, etc. etc., are not purely resistive so calculating resistance is meaningless for practical purposes.
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What is transducer and how it may be used to measure displacement?
Transducer is a device which convert physical signal into electrical signal ( current/voltage/resistance). for linear measurement we can use LVDT (Linear Variable Displacement Transducer/ Linear Variable Differential Transformer). and for rotary measurement we can use RVDT (Rotary Variable Differential Transformer)
Define Internal Resistance?
The internal resistance of a device is the resistance in ohms of that device. It is the resistance electrons need to overcome before electricity is said to flow.
What check should be done to an electrical measuring device before attempting to measure electrical resistance?
An electronic measuring device also known as a multimeter is used to check the electrical voltage in homes and industrial areas. The checks that need to be done before a multimeter is used is the to plug the black test lead into the black socket marked com. The red lead plugs into the red socket marked voltage and resistance.
What is described as a device with specific resistance and is used to control current?
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How do you measure electrical insulation resistance value?
By Megger testing (meggering) of the motor any one can measure the IR of the motor. MEGGER is a device used to measure IR. Analog Megger device may generate 500 volts..it gives coil to coil or coil to body IR value...it should not be less than 2 Mega ohm, generally it should be or kept more than 5 mega ohm...thanks ...DEEPAK RAJPUT
