Which two instruments are primarily used to check continuity or measure resistance in a circuit?

The correct choice involves understanding the functions of specific instruments used in electrical measurements. An ohmmeter is specifically designed to measure resistance in circuits, providing a direct readout of resistance in ohms. It applies a small voltage to the component or circuit under test and measures the current that flows, allowing for the calculation of resistance based on Ohm's Law.

Similarly, a Megger is a specialized type of ohmmeter used particularly for insulation resistance testing. It applies a high voltage to check the integrity of insulation around electric wiring, measuring the resistance to ground to ensure that the insulation is intact and not allowing current to leak.

Both instruments are essential for continuity checks, as they can indicate whether a complete path exists for current to flow, which is critical in diagnosing and troubleshooting circuits. In contrast, the other options listed comprise instruments primarily used for different purposes such as signal analysis, frequency measurements, or current and voltage measurements, rather than specifically focusing on resistance or continuity testing.