Advertisements
Advertisements
Question
Define the term resistivity and state its S.I. unit. Which will have higher resistivity a conductor or an insulator.
Advertisements
Solution
The resistivity of a substance is the resistance of a wire of that substance of unit length and unit area of cross-section. Its S. I. unit is ohm × m. An insulator will have higher resistivity.
RELATED QUESTIONS
Name a substance of which the resistance remains almost unchanged by the increase in temperature.
What potential difference is needed to drive a current o f 1 A through a 5 Ω resistor?
To increase the effective resistance in a circuit, the resistors are connected in _______________ .
Choose the correct alternative and rewrite the following:
You are given three equal resistances. In how many combinations can they are arranged?
Write an expression for calculating electrical power in terms of current and resistance.
State a relation between electrical power, resistance and potential difference in an electrical circuit.
In the circuit shown below, calculate the equivalent resistance between the points (i) A and B, (ii) C and D.
Calculate the value of the resistance which must be connected to a 15 ohm resistance to provide on effective resistance of 6 ohm.
Show how you would connect three resistors, each of resistance 6 Ω, so that the combination has a resistance of 4 Ω.
