Question

If the pointer of a galvanometer isn’t right at zero of the scale then the error is called:
A) Instrumental error
B) Systematic error
C) Personal error
D) Random error

Answer 1

Hint: A galvanometer is an instrument used to detect small electric current and measure its magnitude. It utilises a magnetic needle’s movement or that of a coil placed in a magnetic field to indicate the current or its intensity.

Complete step by step solution:
In regular circumstances, when no current passes through the galvanometer, the pointer stays at rest at the zero of the scale. But sometimes, galvanometers can develop errors due to multiple reasons like the aging of the instrument, presence of permanent magnets and the spring getting damaged to mechanical stress. Due to creation of such errors, the pointer of the galvanometer fails to point at the zero of the scale. Such an error is called instrumental error as it is an error in an electrical instrument.
An instrumental error can, on rare occasions, also develop if the circuit isn’t connected in a proper manner.

Thus, the correct option is (A) Instrumental Error.

Additional Information: A moving coil galvanometer is a current carrying coil placed in an external magnetic field that experiences magnetic torque. The angle of deflection of the coil due to the effect of the magnetic torque is proportional to the magnitude of the current passing through the coil.

Note: While choosing a galvanometer for your laboratory experiments, be careful to always check for instrumental errors as it could affect the data in your experiment and hinder your progress. Also make sure to connect the circuit in the way as advised by your teachers so as to not cause any instrumental errors on your own.