Question 31 QMED02 - Electrician-Refrigerating Engineer

The Correct Answer is C **Explanation of why Option C ("switch position "6" and terminal jacks "1 and 4"") is correct:** To measure DC current in the milliamps (mA) range, two primary selections must be made on the meter (as defined by illustration EL-0047): 1. **Switch Position:** The selector switch must be set to the DC Milliamps (DC mA) function and range. Position "6" is designated for the DC current (mA) measurement function, and depending on the specific range selected within that position, it handles currents up to a specific limit, which usually includes 200 mA. 2. **Terminal Jacks:** For general voltage, resistance, and standard low/medium current (milliamps) measurements, the test leads must be inserted into the jacks designated for these functions. Jack "4" is the common (COM) terminal, and Jack "1" is the main input terminal for V/$\Omega$/mA. This configuration correctly places the meter in series with the circuit to measure DC current up to 200 mA. **Explanation of why the other options are incorrect:** * **A) switch position "7" and terminal jacks "1 and 4":** While terminal jacks "1 and 4" are correctly used for mA measurements, switch position "7" is typically designated for measuring Resistance ($\Omega$), AC Volts (V~), or a different, non-milliamps range. Therefore, the function/range selector is incorrect. * **B) switch position "6" and terminal jacks "2 and 4":** Switch position "6" correctly selects the DC mA range. However, terminal jack "2" is almost universally designated as the high-current input (e.g., the 10-Amp unfused or fused input). Using jack "2" for a 200 mA measurement is incorrect and would bypass the necessary mA shunt resistor circuitry, often requiring the range switch to be set to a high-Amp setting instead of the mA setting. * **D) switch position "7" and terminal jacks "2 and 4":** Both the switch position "7" (incorrect function) and the terminal jacks "2 and 4" (incorrect leads for mA measurement) are wrong for measuring a 200 mA DC current. This configuration is usually reserved for a high-Amp AC or DC measurement (using Jack 2) or a completely different function (using Position 7).