Question

Two resistances R1 and R2 are joined in parallel to a source of emf of negligible internal resistance. The power developed in R2 is P. If R1 is now removed, the power developed in R2 will be:

A) greater than P for all values of R1 and R2
B) less than P for all values of R1 and R2
C) P for all values of R1 and R2
D) P only if R1 = R2.

Answer 1

When R1 is removed from the parallel circuit, the power developed in R2 will be greater than P for all values of R1 and R2.

Step-by-step explanation:

When resistors are connected in parallel, the total resistance is lower than the smallest individual resistance. This means that more current flows from the source in a parallel circuit compared to each resistor individually.

Since power is calculated using the formula P = V²/R, where V is the voltage and R is the resistance, a lower resistance connected to a given voltage source will result in greater power delivered.

Therefore, when R1 is removed from the parallel circuit, the total resistance decreases. As a result, the power developed in R2 will be greater than P for all values of R1 and R2.