Question

A circuit contains three resistors connected in parallel. The value of R1 is 2 K , the value or R2 is 6 K , and the value of R3 is 10 K . If the supplied voltage is 100 VDC, what is the total power in the circuit

Answer 1

In a parallel connection, the voltage is same in every branch.
Now, three three resistors connected in parallel.
R1 = 2k ohm
R2 = 6k ohm
R3 = 10k ohm
in parallel, net resisitance  = $\frac{ R_{1}R_{2}R_{3} }{R_{1}R_{2} + R_{2}R_{3} + R_{3}R_{1}}$

Now, putting the values, we get, R net = 1.30 k ohm.
Ans, voltage = 100 VDC
Thus, power = $\frac{ V^{2} }{R} = \frac{ 100^{2} }{1.3 k} \\ \\ where \\ k = 10^{3}$ 
                      = 7.69 Watt