Physics · Current Electricity

All of the instruments listed—Wheatstone Bridge, Meter Bridge, Post Office Box, and Ohmmeter—are used for measuring resistance:Wheatstone Bridge: Measures resistance by balancing two legs of a bridge circuit.Meter Bridge: Functions similarly to a Wheatstone Bridge and is often used in educational settings for practical demonstrations.Post Office Box: A form of the Wheatstone Bridge designed for precision resistance measurements.Ohmmeter: Directly measures electrical resistance and is commonly used in various applications.Each tool has its own specific applications and advantages, making them all valid for this purpose. The other options are incorrect because they exclude one or more instruments that can also measure resistance.

A Wheatstone Bridge is indeed used for measuring resistance by balancing two legs of a bridge circuit. However, this is not the only instrument that can measure resistance.

Both the Wheatstone Bridge and the Meter Bridge, which operates on a similar principle, can measure resistance. However, other instruments in the list also serve this purpose.

While the Meter Bridge and the Post Office Box are used for resistance measurement, they are not the only instruments in the given list that can do so.

The Post Office Box and the Ohmmeter are both used to measure resistance, but this choice excludes other valid instruments from the list.

All listed instruments are capable of measuring resistance: the Wheatstone Bridge, Meter Bridge, Post Office Box, and Ohmmeter each have unique methods or applications for doing so.