Question

Three 2100 Ω resistors, all in parallel, are connected across a 210-V dc source. Calculate (a) the

total current, (b) the current through each resistor, and (c) the total power dissipated in the resistors.

Answer 1

Explanations & Calculations

• Just refer to the formula for resistors in parallel.
• This will lead you to the answer, $\large \frac{2100\Omega}{3}=\small 700\Omega.$

• The same current flows through each resistor as each one is identical.
• Use Ohm's law to find the current, $\small I=\large\frac{V}{R}=\frac{210\,V}{700\,\Omega}=\small 0.3\,A$

• The power dissipated (heat) is given by $\small p=I^2R$ for a resistor.
• You can use this formula for this step.
• Total power dissipation is 3 times that of one.
• You know the current through a resistor and their resistance, so you can give it a try.
• Unit should be Joules(J)