Voltage and Current - Technical MCQs

Q1:

A multimeter measures only voltage.

A True

B False

ANS:B - False

I said that it only measures voltage, because actually that is the only thing which CAN be measured by a digital multimeter.

When you select "OHMS" on a multimeter, voltage is measured by passing a constant current source through the resistor and measuring the VOLTAGE across the resistor. A microprocessor then calculates resistance using ohm's law, R=V/I.

When you select "CURRENT" on a multimeter, voltage is measured across a shunt resistor in series with the load, and then the microprocessor calculates current using ohm's law, I=V/R.

Hence one can argue that a multimeter only measures voltage, but rather calculates resistance and current also.