Galvanometer Function and Principles

The video tutorial explains the moving coil suspended type galvanometer, a device used to measure small electric currents accurately. It operates on the principle that a current-carrying coil in a magnetic field experiences a torque proportional to the current. The construction involves a coil wound on a soft iron core, suspended between magnet poles, with a concave mirror for deflection measurement. The working principle involves torque causing coil deflection, balanced by a restoring torque, with the galvanometer constant relating current to deflection.

What is the primary function of a galvanometer?

• To measure resistance

• To measure feeble current

• To measure power

• To measure voltage

On what principle does a moving coil galvanometer operate?

• Electromagnetic induction

• Thermal expansion

• Electrostatic force

• Torque on a current-carrying coil in a magnetic field

What material is used for the coil in a moving coil galvanometer?

• Iron

• Silver

• Aluminum

• Copper

What is the purpose of the phosphor bronze strip in the galvanometer?

• To provide electrical insulation

• To suspend the coil

• To measure deflection

• To generate magnetic field

What is the role of the concave mirror in the galvanometer?

• To measure deflection

• To focus light on the coil

• To protect the coil

• To generate torque

How is the deflection in the coil of a galvanometer determined?

• By a digital display

• By a lamp and scale arrangement

• By a sound signal

• By a mechanical pointer

What happens to the coil when a current passes through it in a galvanometer?

• It remains stationary

• It rotates due to torque

• It expands

• It contracts

What is the angle between the normal to the plane of the coil and the magnetic field in a radial field?

• 0 degrees

• 45 degrees

• 90 degrees

• 180 degrees

What is the restoring torque in a galvanometer proportional to?

• The length of the coil

• The magnetic field strength

• The angle of deflection

• The current

What is the galvanometer constant 'G' defined as?

• AB by K NA

• K by NA AB

• NA by K AB

• K AB by NA