A switchboard ammeter indicates a reading slightly above 'zero' when the leads are disconnected. What is this caused by?
⢠Analog ammeter construction (moving coil, pointer, mechanical zero adjustment) ⢠Difference between electrical causes (grounding, charge, capacitance) vs purely mechanical causes ⢠Behavior of a meter when leads are open-circuited (no current path)
⢠If the leads are disconnected, is there any complete circuit for current to flow through the meter? What does that suggest about electrical vs mechanical causes? ⢠Which of the options would still be present and have an effect even if there were absolutely no voltage or current applied to the meter? ⢠Think about how the meter pointer is initially set to zero at the factory or during calibration. Which answer choice relates directly to that process?
⢠Verify which option would affect the pointer even with no electrical connection at all ⢠Eliminate options that require current flow or stored electrical energy when the leads are open ⢠Focus on the cause that is inherent to the meter movement and pointer rather than external electrical conditions
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