Basic hardware check: When measuring a typical internal PC speaker with an ohmmeter (disconnected from the circuit), which resistance value is most appropriate to expect?

Introduction / Context:Technicians sometimes verify small speakers with a multimeter to ensure the voice coil is intact. The reading provides a quick check before deeper audio troubleshooting.

Given Data / Assumptions:

• The internal PC speaker or small transducer is disconnected prior to measurement.
• We expect a finite, low DC resistance for a good voice coil.
• Nominal impedances for small speakers are typically 4, 8, or 16 ohms (AC impedance at audio frequencies), with DC resistance somewhat lower but in the same range.

Concept / Approach:

A healthy dynamic speaker presents a small, nonzero resistance when measured with DC. Although its rated impedance is specified at AC, the DC resistance is typically a bit less than that rating. Among the choices, 16 ohms is the only reasonable finite value in the expected range. Values like a negative resistance, “Q Ohms,” or infinite (open circuit) would indicate measurement error or a blown coil.

Step-by-Step Solution:

Verification / Alternative check:

An audio test with a function generator or motherboard beep confirms operation; an open coil reads very high resistance and produces no sound.

Why Other Options Are Wrong:

• Q Ohms: Nonsensical value.
• -200 Ohms: Negative resistance is not applicable here.
• Unlimited Ohms: Indicates an open, failed coil.
• None of the above: Incorrect because 16 ohms is plausible and correct among the options.

Common Pitfalls:

Measuring in-circuit leading to misleading values; confusing rated impedance with DC resistance; not disconnecting power before testing.

Final Answer:

16 Ohms