Question

Why should the resistance of :
a) an ammeter be very small
b) an voltmeter be very large

Answer 1

a) because we don't want a current measuring device to affect current much in a circuit.
b) so less current flow through it thus not affecting our main goal of measuring voltage across a resistor/battery/etc

Answer 2

Answer: a)so that the ammeter may not charge the value of current flowing.in it

B)so that the voltmeter takes negligible current from it

Regards