Question

Resistances 1 Ω, 2 Ω and 3 Ω are connected to form a triangle. If a 1.5 V cell of negligible internal resistance is connected across the 3 W resistor, the current flowing through this resistor will be(a) 0.25 A(b) 0.5 A(c) 1.0 A(d) 1.5 A

Answer 1

Assuming u meant across the 3Ω resistor,

The combination is such that the 1& 2Ω resistors are in series and both of them are in parallel to the 3Ω resistor. Therefore, this can be considered as two 3Ω resistors in parallel.

Therefore, net resistance in circuit = 3/2 Ω( Resistance in parallel formula)

                                                          = 1.5Ω

We know that

V = IR

as the battery is of 1.5V and the net resistance is 1.5Ω

V/R = I

1.5V / 1.5Ω = I

I = 1A