A Voltmeter, an ammeter (Ampere meter) and a battery cell are connected in series. It is observed that ammeter practically shows No Deflection. Why?

Due to the large resistance of the voltmeter, the circuit resistance becomes very high. As a result, very small current will flow in the circuit. this small current f on passing through the coil of voltmeter will produce some deflection. However, in case of ammeter (Ampere meter), most of this small current will flow through the shunt. Consequently the deflection of the ammeter will be practically nil.