Which device is used to detect very small electrical currents in a circuit by measuring magnetic deflection?

Which device is used to detect very small electrical currents in a circuit by measuring magnetic deflection?

• A. Galvonometer
• B. Transformer
• C. Generator
• D. Solenoid

Answer: (A)

Detecting very small currents by turning electrical flow into a measurable mechanical movement relies on a coil in a magnetic field that experiences a torque when current passes through it. A galvanometer uses a moving coil placed in a strong, uniform magnetic field. When current flows, magnetic forces on the coil produce a torque that turns the coil and a lightweight pointer. The pointer’s deflection is read on a scale and is proportional to the current (within the device’s linear range), giving a highly sensitive indication of tiny currents. This principle—current through a coil causing magnetic deflection—is what makes the galvanometer ideal for detecting very small currents. Transformers change voltage and current levels and aren’t detectors of small currents by deflection. A generator is a source of electrical energy, not a detector. A solenoid is just a coil that can create a magnetic field or actuate motion, not a sensitive current detector by measuring deflection.

Detecting very small currents by turning electrical flow into a measurable mechanical movement relies on a coil in a magnetic field that experiences a torque when current passes through it. A galvanometer uses a moving coil placed in a strong, uniform magnetic field. When current flows, magnetic forces on the coil produce a torque that turns the coil and a lightweight pointer. The pointer’s deflection is read on a scale and is proportional to the current (within the device’s linear range), giving a highly sensitive indication of tiny currents. This principle—current through a coil causing magnetic deflection—is what makes the galvanometer ideal for detecting very small currents.

Transformers change voltage and current levels and aren’t detectors of small currents by deflection. A generator is a source of electrical energy, not a detector. A solenoid is just a coil that can create a magnetic field or actuate motion, not a sensitive current detector by measuring deflection.