1. Circle whether each statement is True or False.
Using a small gear ratio increases the speed from the input to the output.
A DC motor can produce high rotational speed and high torque at the same time.
Power increases as you go from a small gear to a large gear (large gear ratio).
An input gear (driver) is easier to turn when a larger gear ratio is used.
Flowing current causes a magnetic field.
DC motors and generators are totally different mechanisms.
Force must be applied perpendicularly to a length in order to produce torque.
Power can be increased by adjusting the gear ratio.
2. Write the equations used to calculate a) rotational power output of a motor and b) electrical power output of a generator. Make sure to define all variables (what do the variables mean and what units are they in).
3. For the gear train shown below, a DC motor is connected to Gear A. It has been determined that the motor is applying a torque of 3 N-m to Gear A causing it to rotate. Gear A is 'meshed' with Gear B, which is connected to a generator. Use this gear train to answer the questions below.
What is the gear ratio of this gear train? Show your calculations! (Hint: which is the input gear and which is the output gear) Show in ratio form.
(b) If the rotational speed (angular velocity) of gear B is 4 rad/s, what is the rotational speed of gear A? Show your calculations! (Hint: Should Gear A rotate faster or slower than Gear B?)
(c) How much rotational power is supplied by the motor? (Hint: remember, the motor is applying a torque of 3 N-m to Gear A) Show your calculations!