Question

Why permanant magnet is used instead of electromagnet in ammeter and speedometer and microphone ?

Answer 1

Dear Student ,

permanent magnets are used in ammeter ,speedometer and microphone because :

• Higher efficiency since no electrical energy is used or losses incurred for developing or maintaining the motors magnetic field.
• Higher torque and power density.
• Linear torque speed charcteristics.5that are more predictable.
• Better dynamic performance due to higher magnetic flux density in air gap.
• Simplified construction and essentially maintenance-free.
• More compact size.

Regards