Why the resistance of an ideal ammeter is zero?
An ideal ammeter would have zero resistance so that there was no voltage drop across it, and so it would not affect a circuit into which it was placed. A zero resistance will not change the resistance of a circuit is placed in series and hence would not change the current in the circuit.
What is the value of the resistance of an ammeter zero?
Resistance of an ideal Ammeter is zero and that of an ideal voltmeter is infinite. A voltmeter and an ammeter are connected in the circuit as shown.
What happens when an ammeter is not ideal?
If the Ideal Ammeter resistance is not nearly zero when it is connected in series to measure the current in the circuit/load it would result in drop of voltage in Ammeter which would alter the current in the circuit which we intended to measure.
Why is it important to zero the voltmeter?
An ammeter is used to measure the current in the circuit. For it, the ammeter is connected in series of the circuit. The current measured by ammeter will be accurate if there is no change in current of the circuit by the use of ammeter in series of circuit. Thus ideal ammeter has zero resistance.
What properties should an ideal voltmeter have?
An ideal voltmeter would have infinite resistance, a foolproof system to prevent exposure to excess voltage (auto ranging), and be free for the asking. An ideal ammeter would have zero resistance and a foolproof system to prevent exposure to excess voltage (auto ranging), and again free for the asking.
What causes negative voltage?
Re: how do we have a voltage below zero? A negative voltage is a relative excess of electrons compared to some other point. If 0 V is no voltage. Negative voltage is an excess of electrons and positive voltage is a deficiency of electrons.
What is the difference between negative and positive voltage?
The difference between positive and negative voltage is analogous to the difference between positive and negative pressure (i.e., a vacuum). In the case of voltage, positive or negative simply refers to the polarity of the voltage relative to some reference point.