Practice Exercise 1B

A wire of resistance$20 \Omega$ is bent in the form of closed circle. The effective resistance between two points at the ends of any diameter of the circle is _____ $\mathrm{\Omega }$.

The effective resistance between A and B is $\mathrm{K} \mathrm{ohms}$. Find the value of $\mathrm{K}$ up-to two decimals.

Calculate the effective resistance (in ohms) between A and B.

Calculate the effective resistance between A and B. Also find the reading of ammeter and voltmeter.

In the given circuit calculate
(i) the total resistance of the circuit
(ii) current flowing through the circuit
(iii) Potential difference across (a) the lamp and (b) resistor.

A piece of wire of resistance $20 \Omega$ is drawn out so that its length is increased to twice its original length. Calculate the resistance (in ohms) of the wire in this new situation.

(Choose among the following: $40 /80 /400$)

Study the following electric circuit and find potential difference (in volt) across $4 \mathrm{\Omega }$ resistor.

State four different ways in which three resistors of $\text{'}r\text{'}$ ohm each may be connected in a circuit. In which case is the equivalent resistance of the combination minimum?