Three resistors of 2Ω, 5Ω and 8Ω are connected in series to a variable dc supply. Each resistor is rated to withstand a maximum power of 20W.
a. (i) Determine the maximum current the circuit can safely carry.
b. (ii) For this current, calculate the supply voltage required.
c. (iii) If the current is slowly increased beyond this value, which resistor will reach its power limit first? Give a reason.