Question

1) An ideal ammeter would have zero resistance while an ideal voltmeter would have infinite resistance, why?

2) Is the true resistance greater or smaller than the measured resistance?

3) What is sweep time of a scan with a sweep rate of 60 Hz?

4) Is the time base affected by changing the horizontal and vertical gains?

5) What is an ohm, what combination of fundamental SI units does it represent?

6) The common 9 Volt battery imparts how much energy to one coulomb of charge?

Answer 1

1)   Ammeter measures current flowing through a circuit and is connected in series. If the ammeter doesn't have low resistance ( zero in ideal case) it will increase the resistance of actual circuit and the original current cannot be measured. So ideal ammeter resistance should be zero so that the ammeter's resistance doesn't contribute in circuit.

Voltmeter measures potential difference of two points in a circuit. Now if the resistance of voltmeter is not high ( infinite in ideal case) current will flow through voltmeter and the reading of potential difference of two points will be changed. So actual potential difference cannot be measured. So ideal voltmeter resistance should be infinite.