Question

If the wheel diameter, gear ratio and speed of the vehicle are all halved. What will be
its effect on the rpm of the electric motor? Choose the correct option.
a) It will become twice.
b)It will become half.
c)No change.
d)It will become four times.

Answer 1

If the wheel diameter, gear ratio and speed of the vehicle are all halved. What will be  its effect on the rpm of the electric motor will have no change.

• we know, mathematically, velocity (v) = radius (r) * angular velocity (ω)
• So, ω = v / r
• Again, ω = 2 * Pi * N / 60 Here N = rpm of the motor.
• So, N is directly proportional to the velocity of the vehicle and inversely proportional to the radius of the motor.
• So, when both velocity and the diameter are halved, the rmp will have no change.