The correct answer is: A galvanometer with high resistance in series is an ammeter.
A galvanometer is a device that measures electric current. It consists of a coil of wire that is suspended in a magnetic field. When current flows through the coil, it creates a magnetic field that interacts with the external magnetic field, causing the coil to move. The amount of movement is proportional to the amount of current flowing through the coil.
A voltmeter is a device that measures voltage. It consists of a galvanometer and a high resistance in parallel. The high resistance limits the amount of current that flows through the galvanometer, so that the voltage drop across the galvanometer is proportional to the voltage being measured.
An ammeter is a device that measures current. It consists of a galvanometer and a low resistance in series. The low resistance allows a large amount of current to flow through the galvanometer, so that the deflection of the needle is proportional to the current being measured.
In option A, a galvanometer with low resistance in parallel is a voltmeter. This is incorrect because the low resistance will allow too much current to flow through the galvanometer, causing it to be damaged.
In option B, a galvanometer with high resistance in parallel is a voltmeter. This is incorrect because the high resistance will limit the amount of current that flows through the galvanometer, so that the voltage drop across the galvanometer is not proportional to the voltage being measured.
In option C, a galvanometer with low resistance in series is an ammeter. This is incorrect because the low resistance will allow too much current to flow through the galvanometer, causing it to be damaged.
In option D, a galvanometer with high resistance in series is an ammeter. This is correct because the high resistance will limit the amount of current that flows through the galvanometer, so that the deflection of the needle is proportional to the current being measured.