Electrical Engineering - Energy and Power - Discussion

Heated beyond a safe or desirable point is over heating so just pay attention on words of question when both are connected to same source and no external power conditions are changing then why are you so confuse Option D is ok.

Less resistance more current and more current more heating.

Since both resistors are connected across the voltage is in parallel so the option D is correct.

The question has two key words: half-watt, and (connected) across. The resistors are designated to work up to half-watt power, more than it make them overheat. If the word across is used, it means the resistors are connected in parallel. Therefore,

R1 = 33 ohm, and its power dissipation is P1 = V*I1 = 12*12/33 = 4.3W.
R2 = 330 ohm, and its power dissipation is P2 = V*I2 = 12*12/330 = 0.43.
P1 = 4.3W>0.5W, and P2 = 0.43W<0.5W,

Hence, R1 = 33ohm is overheat, option A is the correct answer.

Current is same through resisters connected in series.

As per the given question both are equal wattage so given two resistors never get over heated. So the answer is option D.

Answer is wrong. Because we doing in project side in small value of resistors are easily access the heat.

It is [A] 33 W will overheat, because its wattage VI = 12*12/33 = 4.36 W against the allowed 0.5 W. For 330 W, wattage = 12*12/330 = 0.436 W within the 0.5 W.