Consider the network of four resistors shown in the diagram, where R 1 = 2.00 ,
ID: 1328434 • Letter: C
Question
Consider the network of four resistors shown in the diagram, where R1 = 2.00 , R2 = 5.00 , R3 = 1.00 , and R4 = 7.00 . The resistors are connected to a constant voltage of magnitude V. (Figure 1)
Find the equivalent resistance RA of the resistor network.
Two resistors of resistance R5 = 3.00 and R6 = 3.00 are added to the network, and an additional resistor of resistance R7 = 3.00 is connected by a switch, as shown in the diagram..(Figure 2) Find the equivalent resistance RB of the new resistor network when the switch is open.
Explanation / Answer
the resistors in parallel
1 / Req = 1 / R1 + 1 / R2 ...............
resistors in series
Req = R1 + R2 ..............
in the circuit
R1 and R2 are in parallel
therefore 1 / (1 / R1 + 1 / R2)
and then this will sereis with R3 and R4
Ra = R3 + R4 + 1 /( 1/R1 + 1 / R2)
Ra = 1 + 7 + 1 / ( 1 / 2 + 1 / 5 )
Ra = 9.42 ohm