Which of the following is measured by a digital multimeter?

A digital multimeter is a versatile instrument used primarily for measuring electrical parameters. The correct answer focuses on the three fundamental electrical measurements that a multimeter can accurately perform: voltage, amp draw (current), and resistance.

Voltage measurement allows the user to determine the electrical potential difference between two points in a circuit, while current measurement (amp draw) quantifies the flow of electrical charge in amperes. Additionally, measuring resistance helps assess the continuity and integrity of electrical components and circuits. This combination of capabilities makes digital multimeters essential tools in troubleshooting and maintenance of electrical systems, including small engines.

The other options, while they may pertain to measurements that can be taken with specialized devices, do not encompass the primary functions of a digital multimeter as directly as voltage, current, and resistance do. For instance, temperature and humidity are monitored using separate environmental sensors and meters, and frequency and capacitance can be measured with specific tools designed for those parameters. Current and power factor might require additional specialized equipment, particularly in more complex electrical systems.