Question

Three resistors A,B,C are connected as shown in the figure.Each of them dissipates energy to maximum of 18 W .Find the maximum current that can flow through the circuit.

Answer 1

where is the figure.............

Answer 2

Answer:

V= voltage across a resistor

I = current through the resistor

R = value of resistance.

Power  dissipated by the resistor is given by : P =  V²/R = I² R

      I² = P / R

Each resistance dissipates energy = 18 Watts

Maximum current through B or C or A is given by : I² = 18 Watts/2 ohms

          So I = 3 Amperes maximum

Since the resistances B and C are connected in parallel, the current that comes from the resistance A is divided equally between the resistance B and C.

  so current through  B = current through resistance C = 1/2 * current thru A

Since, the current passing thru resistor A is max = 3 ampere, then the current through resistor B and resistor C  are 1.5 Amperes maximum.