Question

draw circuit diagram of an electric circuit containing a cell a key and ammeter a resistor of 4 ohm in series with a combination of two resistors 8 ohm each in parallel and a voltmeter across parallel combination each of them dissipate maximum energy can with stand a maximum power of 16 watt without melting find the maximum current flow through the three register

Answer 1

See the attachment , I drew the circuit in which a resistor of resistance 4Ω is attached in series and two resistors of resistance 8Ω are attached in parallel . Also Ammeter and voltmeter attached in circuit in series and parallel respectively.

Now, come to the question ,

Maximum power of each resistor is 16W

4Ω resistor is joined in series with circuit .

so, Power = i² R , here i is current through resistor of resistance R

16 = i² × 4Ω

i = 2A

Now, 2A is passing through parallel resistors of resistance 8Ω.

we know, in parallel potential difference be constant

so, current divides two part , due to same resistance current on each resistance will be half . so, current passing through each parallel resistor is 2/2A = 1A

So, finally current through 4Ω resistor = 2A

current through each 8Ω resistor = 1A