A resistor has a resistance of 176 ohms. How many of these resistors should be connected in parallel so that their combination draws a current of 5 amperes from a 220 volt supply line?

The circuit diagram given below shows the combination of three resistors R₁, R₂ and R₃ :

Find:

(i) total resistance of the circuit.

(ii) total current flowing in the circuit.

(iii) the potential difference across R₁.

In the circuit diagram given below, the current flowing across 5 ohm resistor is 1 amp. Find the current flowing through the other two resistors.

An electric heater which is connected to 220 V supply line has two resistance coils A and B of 24 Ω resistance each. These coils can be used separately (one at a time), in series or in parallel. Calculate the current drawn when:

(a) only one coil A is used.

(b) coils A and B are used in series

(c) coils A and B are used in parallel.

In the circuit diagram given below five resistances of 10 Ω, 40 Ω, 30 Ω, 20 Ω and 60 Ω are connected as shown to a 12 V battery.

Calculate:

(a) total resistance in the circuit.

(b) total current flowing in the circuit.