Step 1: Finding Resistance (R)
We use the formula for resistance when the rated voltage (V) and rated power (P) are given:
R=PV2
Given:
V=200volts,P=50watts
Substituting the values:
R=502002=5040000=800Ω
Thus, the resistance is:
R=800Ω
Step 2: Finding Power (P) for a Different Voltage
To calculate the power consumed for an applied voltage (Vapplied) of 100 volts, we use the formula:
P=RVapplied2
Given:
Vapplied=100volts,R=800Ω
Substituting the values:
P=8001002=80010000=12.5watts
Thus, the power consumed is:
P=12.5watts