This circuit, called a Wheatstone bridge, is useful for making precise resistanc
ID: 2018152 • Letter: T
Question
This circuit, called a Wheatstone bridge, is useful for making precise resistance measurements. The potential difference measured by the voltmeter in the middle depends on the relative resistances of the four resistors. If that potential difference is zero, the Wheatstone bridge is said to be balanced. Suppose you balance the Wheatstone bridge in the figure by adjusting the variable resistor to 65.0 ohms. What is the resistance of R1? (Hint: Because the bridge is balanced, the potential difference across R1 equals that across R2. The same relation holds between Rvariable and R3)
Explanation / Answer
R1/129=65/8665/86*129=97.5