Question

a. Heat energy is being produced in a
resistance in a circuit at the rate of
100 W. The current of 3 A is flowing
in the circuit. What must be the
value of the resistance?(Ans: 11 S2)​

Answer 1

Answer:

Given that,

Power, P=100W

Current, I=3A

Power,

P=VI

p= I^2 r

r= p/i^2

so,

r= 100/9

R=11.1Ω

Answer 2

S O L U T I O N :

$\underline{\bf{Given\::}}$

• Rate of power, (P) = 100 Watt
• Current, (i) = 3 Ampere

$\underline{\bf{Explanation\::}}$

As we know that formula of the electrical power;

$\boxed{\bf{P = i^{2}R}}$

$\underline{\underline{\tt{According\:to\:the\:question\::}}}$

$\mapsto\tt{100 = (3)^{2}\times R}$

$\mapsto\tt{100 = 3 \times 3\times R}$

$\mapsto\tt{100 = 9\times R}$

$\mapsto\tt{R = \cancel{\dfrac{100}{9} }}$

$\mapsto\bf{R = 11.11\:\Omega}$

Thus,

The value of the resistance will be 11.11 Ω .

Note :

• 1 horse power = 746 Watt.
• Number of joules in kilowatt-hour = 3.6 × 10^6
• The unit of electric power = Watt (W) .
• The commercial unit of electrical energy = kilowatt-hour, (kwh).
• 1 kwh = 3600000 joules .