Explain the difference between static balance and dynamic balance and why both matter for rotating drives.

• A. Static balance prevents net torque when stationary; dynamic balance prevents vibration at speed; both reduce wear and noise.
• B. Static balance ensures symmetry of the rotor; dynamic balance has no effect.
• C. Static balance relates to belt tension; dynamic balance relates to gear ratio.
• D. Static balance prevents vibration at start; dynamic balance prevents heat buildup.

Answer: (A)