Answer: b) IR2
Electrical power is given by the expression P = VI. (1)
According to Ohm’s law,
V = IR
Substituting the value of V in (1), we get
P = (IR) × I
P = I 2R
Similarly, from Ohm’s law,
I = V/R
Substituting the value of I in (1), we get
P = V × V/R = V 2 /R
From this, it is clear that the equation IR2 does not represent electrical power in a circuit.Answered by Shivani Kumari | 2 years ago
Explain the following.
a. Why is the tungsten used almost exclusively for filament of electric lamps?
b. Why are the conductors of electric heating devices, such as bread-toasters and electric irons, made of an alloy rather than a pure metal?
c. Why is the series arrangement not used for domestic circuits?
d. How does the resistance of a wire vary with its area of cross-section?
e. Why copper and aluminum wires are usually employed for electricity transmission?