Question

(a) Out of galvanometer, ammeter and voltmeter which has the highest resistance and which has the lowest?
(b) Which of the two meters has lower resistance a milliammeter ar a microammeter?

Answer 1

Hey mate!

Here's your answer!

(a) Ammeter measures current and is joined in series with the circuit. 

Therefore, it must have very low resistance so that it does not oppose current. If it has high resistance it will not draw all the current and measurement will not be precise. 

(b) The resistance of a current carrying conductor is inversely proportional to the area of cross section of the conductor. When area of cross section of the conductor increases, the gap between electrons increases. So the probability of collision decreases. As a result the resistance decreases. Hence, milliammeter will have low resistance.

Hope it helps :)