Question

two resistance , a 60 ohms and an unknown one are connected to a power source in a series arrengment . Power of the unknown resistance is 60 watt. what is the voltage of the power source at the least ? (a) 60 volt (b) 120 volt (c) 140 volt (d) 180 volt​

Answer 1

Answer:

fisrt multiply those then divide

Answer 2

Answer:

The voltage of the power source is atleast 60 Volts .

Explanation:

Given that :

Power of unknown resistance = 60 W

To find :

• Least voltage of power source

Solution:

• Let, the current flowing through the circuit be I.
• Power rating of 60 Ohm resistance = 60I Watt .
• Power rating of unknown resistance is 60 Watt .
• Power rating of source with voltage, V is VI Watt .
• Since, two resistances are in series combination the sum of power across the two resistance is equal to the power of the voltage source.

$VI = (60I + 60)W \\ V = 60 + \frac{60}{I} \: Volts$

• From the above equation, it is evident that least value of V is 60 Volts.