4-5) Rvar Before the advent of ohmmeters (even the Runk analog ones), unknown resistances (Runk) were measured using a Wheatstone bridge. The unknown resistance is placed into the circuit at right as shown. The values of R1 and R2 are extremely well known. The resistance of Rvar is adjusted until the meter R1. -R2 reads no current in the cross branch. The value of Ryar is then read from a dial.

What is the equivalent resistance of the circut? each resistor has value R. Explain each step

Four resistors are connected in parallel across a 200mA independent current source as shown. What is the voltage across the resistors and the current in each resistor?

In the circuit below, there is a drop of 20 V on each resistor. The potential of point A would be * B 80 V G D C.