Question 448Electricity & Electronics - QMED
70% to passIf a digital multimeter is set up as shown in figure "A" of the illustration to test an AC contactor coil, what would the display read if the coil is open-circuited? Illustration EL-0214
A0.03 ohms
B22 ohms
COL ohms
D110 V
AI Explanation
The correct answer is C) OL ohms. When a digital multimeter is set up to measure resistance (ohms) and the circuit being tested is open-circuited, the multimeter will display "OL" (overload) to indicate that the resistance is out of the measurable range. This is because an open circuit has infinite resistance, which the multimeter cannot accurately measure. The other options are incorrect because: A) 0.03 ohms would be an extremely low resistance, which is not typical for an open-circuited AC contactor coil. B) 22 ohms would be a reasonable resistance for a functioning AC contactor coil, but not for an open-circuited one. D) 110 V is the voltage of the AC power source, not the resistance measurement.
Related Questions
Q108:In terms of units, how is the inductance of a coil measured? Q331:Which of the illustrated schematic symbols represents the type of switch picture... Q249:What will happen if you reverse both the field and the armature connections of a... Q440:If the motor shown in the illustration will not start when the "off-run" switch ... Q217:A 125 volt DC motor is rated at 10 kW. What is the current rating of the motor? ...
Ready to test your knowledge?
Take a Electricity & Electronics - QMED Practice ExamOfficial Resources