A wattmeter has a current coil of 0.1 Ω resistance and a pressur...
Ohms resistance and a voltage coil of 100 ohms resistance. The current coil is connected in series with the load and the voltage coil is connected in parallel with the load. The current through the load is 10 A and the voltage across the load is 100 V.
To calculate the power consumed by the load using the wattmeter, we need to calculate the total resistance of the circuit.
The resistance of the current coil is given as 0.1 ohms, and the resistance of the voltage coil is given as 100 ohms.
In series connection, the total resistance is the sum of the resistance of the load and the current coil, which is 0.1 ohms + load resistance.
In parallel connection, the total resistance is given by the reciprocal of the sum of the reciprocals of the load resistance and the voltage coil resistance.
Let's assume the load resistance is R ohms.
So, the total resistance in series connection is 0.1 + R ohms.
The total resistance in parallel connection is 1 / (1/R + 1/100) ohms.
Since the current coil is connected in series with the load, the current passing through the circuit is 10 A.
Using Ohm's Law, V = I * R, we can calculate the voltage across the load.
So, V = 10 * R volts.
Now, using the power formula, P = V * I, we can calculate the power consumed by the load.
P = (10 * R) * 10
P = 100 * R watts.
Since the wattmeter is connected in parallel with the load, it measures the power accurately.
Therefore, the power consumed by the load can be directly read from the wattmeter as 100 * R watts.