Question

Ammeter is used to measure:
(A) Current
(B) Voltage
(C) Charge
(D) Resistance

Answer 1

Hint
Try to recall the different quantities of physics. Given quantities are very common. And more often used in calculation and theory terms. As given above options are quantities that belong to the same chapter so do not mislead. An Ammeter is used in series now and tries to answer the given question with all certainty.

Complete step by step solution
Now jumping straight to the question:
An ammeter is a device used to measure the current in a circuit.
Electric currents are measured in amperes $A$ , which matches its name. Instruments used to measure smaller currents, in the mill-ampere ( $mA$ i.e. ${10^{ - 3}}A$ ) or microampere ( $\mu A$ i.e. ${10^{ - 6}}A$ ) range.
An Ammeter can be used to determine both direct current and alternating current. It can measure a wide range of values because at high values only a small portion of the current is directed through the meter mechanism; a shunt in parallel with the meter carries the major portion. And that is why ammeter is used in series.
In order for an ammeter to determine a device’s current or current in a branch in a circuit, it must be connected in series to that device. This is important because objects in series experience the same current. They must not be connected to a voltage source — ammeters are designed to work under a minimum load , (which directly relates to the voltage drop across the ammeter, normally a small fraction of a volt).
From the above illustration is it clear that Ammeter used to calculate current.
Hence option (A) is correct.

Note
Measurements of voltages and current with standard instruments like voltmeters and ammeters alter the circuit being measured, introducing non-determined. Voltmeters draw some extra current, whereas ammeters reduce the flow of current in the circuit. A galvanometer can also be used as an ammeter when it is placed in parallel with a small resistance R, often called the shunt resistance.