For determination of power of the resistor take the voltmeter and in parallel attach to the resistor in a chain. Then turn on the ampermeter in a chain. Take readings of current and tension, and multiply their values, current power on the resistor as a result will turn out. It is possible to measure resistor power, knowing its resistance and one of values of current or tension or by means of the special device – a wattmeter.
It is required to you
- Current source, ampermeter, voltmeter, ohmmeter and wattmeter.
Instruction
1. Determination of power of the resistor Collect by the voltmeter and the ampermeter an electrical circuit where turn on the resistor, and the ampermeter. Attach the voltmeter to terminals of the resistor. At connection to a DC power source observe rules connections of devices (connect a positive pole of the device to a positive pole of a source of current). After connection of a chain to a source of current take readings of current in amperes (ampermeter) and tension in volts (voltmeter). The received values multiply (P=UI), and as a result receive resistor power in watts.
2. Determination of power of the resistor the voltmeter If resistance of the resistor is known (it is specified directly on its case or measure it by an ohmmeter), connect the voltmeter to its terminals. Connect a collected chain to a current source. Measure value of tension on the resistor in volts. Then square value of tension, and divide into value of resistance (P=U²/R) is and there will be a resistor power.
3. Determination of power of the resistor the ampermeter At the known resistance connect a chain to a current source, having turned on in it consistently the ampermeter. Measure current in a chain by the ampermeter in amperes. Then square value of current and increase by value of resistance of the resistor (P=I²R).
4. Determination of power of the resistor Collect by a wattmeter the chain consisting of the resistor and in parallel to it the connected wattmeter. Having connected it to a current source, you will see resistor power on a scale or the screen of the device. In this case, adjust units of measure within permitted by the device. It can be watts, milliwatts, kilowatts, etc.