JAMB - Physics (2025 - No. 50)
Which of the following is better for measuring a very small resistance?
Voltmeter
Wheatstone bridge
rheostat
Potentiometer
解释
A Wheatstone bridge is specifically designed for the accurate measurement of small and unknown resistances. It operates on the principle of balancing two legs of a bridge circuit, enabling precise determination of resistance values.
Potentiometer: Used to measure potential difference or electromotive force (emf), not to measure resistance directly.
Rheostat: A variable resistor utilized to control current, rather than for measuring resistance.
Wheatstone Bridge: The most effective method for measuring very small resistances.