Final answer:
The correct answer is option d. Digital meters display readings as numerical values and are more accurate than analog meters because they alter the electrical circuit less and have higher (for voltmeters) or lower (for ammeters) internal resistance.
Step-by-step explanation:
The correct answer to the student's question is that digital meters display readings as numerical values. Digital meters are designed to be more accurate than their analog counterparts because they can detect smaller currents. This becomes particularly important when measuring current and voltage. A digital meter uses an analog-to-digital converter to interpret the measurement, which it then displays numerically. This process also means that digital meters can have a higher input impedance as a voltmeter, making it less likely to affect the circuit by introducing a significant load.
Analog meters, on the other hand, use a galvanometer, where current flow causes a needle to move and point to a value on a scale. The resistance of analog meters is lower for ammeters and higher for voltmeters compared to digital meters because of how the measuring mechanism is included in the circuit. Overall, the ability of digital meters to detect smaller currents allows for measurements that alter the circuit less, resulting in more accurate readings.