coil resistance
- Thread starter matey
- Start date
High or Low have a think.
Why is it what it is ( low or high ) ? An ampmeter when inserted in the circuit should make the minimum possible change to the circuit.
Why is it what it is ( low or high ) ? An ampmeter when inserted in the circuit should make the minimum possible change to the circuit.
I will but only provided there is adequate reasoning given for the second part and it is not just a guess. Homework has to be work, not guesses.
<< coil >> I feel a pedantic comment coming on.
<< coil >> I feel a pedantic comment coming on.
DC Ammeters work on the principle that a current passes through a very low resistance called a shunt, and a meter then measures the volt drop across that resistance. The scale is marked in amps but is actually measuring volts. For example 10mV might represent 10A.
If the Ammeter has an internal shunt, then the resistance across the terminals will be very low. But he resistance of the actual coil that produces the deflection of the needle would be high.
AC ammeters work on the principle that a current carrying conductor passes trough the centre of a ring like coil called a current transformer or CT. This induces a small current into a secondary circuit that is connected to a meter. This small current then causes deflection in the meter needle. Again, the resistance of the coil is high.
Or perhaps I am looking too deeply into your question.
If the Ammeter has an internal shunt, then the resistance across the terminals will be very low. But he resistance of the actual coil that produces the deflection of the needle would be high.
AC ammeters work on the principle that a current carrying conductor passes trough the centre of a ring like coil called a current transformer or CT. This induces a small current into a secondary circuit that is connected to a meter. This small current then causes deflection in the meter needle. Again, the resistance of the coil is high.
Or perhaps I am looking too deeply into your question.
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