Assignment:
1. Circle whether each statement is True or False.
True False Using a small gear ratio increases the speed from the input to the output.
True False A DC motor can produce high rotational speed and high torque at the same time.
True False Power increases as you go from a small gear to a large gear (large gear ratio).
True False An input gear (driver) is easier to turn when a larger gear ratio is used.
True False Flowing current causes a magnetic field.
True False DC motors and generators are totally different mechanisms.
True False Force must be applied perpendicularly to a length in order to produce torque.
True False 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.
(a) What is the gear ratio of this gear train?
(b) if the rotational speed (angular velocity) of gear B is 4 rad/s, what is the rotational speed of gear A?
(c) How much rotational power is supplied by the motor?