MATHEMATICS · Multi-part · ISC · Physics · Current Electricity · Ohm's law, V-I graphs and ohmic/non-ohmic conductors
Problem
Three resistors of values 6Ω, 8Ω and 12Ω are connected in parallel across a 24V DC supply in the school laboratory.
(i) Calculate the equivalent resistance of the parallel combination.
(ii) Determine the total power drawn from the source by this combination.
(iii) All three resistors are now replaced by new resistors whose values are exactly double the original ones. Keeping the same 24V supply, calculate the new total power drawn.
(iv) Compare the answers in (ii) and (iii) and explain briefly why the change in resistance produced that effect on the power consumed.