Which meter is commonly used to measure low resistance with a shunt?

Which meter is commonly used to measure low resistance with a shunt?

• A. Shunt
• B. Megohmmeter
• C. Bridge
• D. Ohmmeter

Answer: (A)

Measuring very small resistances needs a path with a known, very low resistance so the meter can read a small voltage drop without being overwhelmed by its own resistance. A shunt provides exactly that: a precisely calibrated low-value resistor placed in the circuit so that current flowing through it creates a voltage drop that a voltmeter or galvanometer can read. From that voltage (and the known value of the shunt) you can calculate the current and then infer the low resistance of the test circuit. This setup also lets you handle larger currents safely while keeping the sensing voltage in a usable range. The other options serve different purposes: a megohmmeter measures high insulation resistance, a bridge is used for high-precision resistance comparisons by balancing, and an ohmmeter measures resistance directly but isn’t as effective for very low values unless paired with a suitable shunt.

Measuring very small resistances needs a path with a known, very low resistance so the meter can read a small voltage drop without being overwhelmed by its own resistance. A shunt provides exactly that: a precisely calibrated low-value resistor placed in the circuit so that current flowing through it creates a voltage drop that a voltmeter or galvanometer can read. From that voltage (and the known value of the shunt) you can calculate the current and then infer the low resistance of the test circuit. This setup also lets you handle larger currents safely while keeping the sensing voltage in a usable range. The other options serve different purposes: a megohmmeter measures high insulation resistance, a bridge is used for high-precision resistance comparisons by balancing, and an ohmmeter measures resistance directly but isn’t as effective for very low values unless paired with a suitable shunt.