(a) Define electric power. Express it in terms of potential difference V and resistance R.
(b) An electrical fuse is rated at 2A. What is meant by this statement?
(c) An electric iron of 1 kW is operated at 220 V. Find which of the following fuses that
respectively rated at 1 A, 3 A and 5 A can be used in it.
Answers
Answer:
(a) electric power is the rate at which electric energy is transferred in a circuit.
power = (voltage^2)/ resistance
p = v^2 / R
(b) This means that he maximum current that can pass through the fuse is 2 A. If any more current flows the fuse will melt and break the circuit.
(c) P = v x i
1000 = 220 x i
i = 1000/220
= 4.5 A
therefore 5 A fuse must be used in it.
Explanation:
Answer:
Explanation:
(a) Electric power: It is the rate of doing work by an energy source or the rate at which the
electrical energy is dissipated or consumed per unit time in the electric circuit is called electric
power.
So, Power P = Work done (w)/Time (t)
= Electrical energy dissipated/Time (t) = Vl = V2/R
(b) It means: the maximum current will flow through it is only 2 A. Fuse wire will melt if the current exceeds 2 A value through it.
(c) Given: p = 1 k W = 1000 W, V = 220 V Current drawn, I = p/V = 1000/220 = 50/11 = 4.54 A To run electric iron of 1 kW, rated fuse of 5 A should be used.