Final answer:
Gear trains with ratios less than 1 are speed multipliers, while those with ratios greater than 1 are force multipliers. Applying more force to Gear A in a gear train increases the torque on Gear B, which may increase its angular velocity if it's part of a speed-increasing train.
Step-by-step explanation:
Gear trains with gear ratios less than 1 are speed multipliers while those with gear ratios greater than 1 are force multipliers. When a gear train has a ratio less than 1, it means that the output gear is rotating faster than the input gear, thus increasing speed but decreasing force. Conversely, when the gear ratio is greater than 1, the output gear rotates more slowly but with greater force than the input gear, hence amplifying the force.
Considering the scenario where Gear A, which turns clockwise, meshes with gear B, which turns counterclockwise, if more force is applied through Gear A, the torque on Gear B increases. If Gear A and B are part of a gear train designed to increase speed, then the angular velocity of Gear B would increase in magnitude (option a). If they are part of a gear train designed to increase force, then more force applied to Gear A would not necessarily change the angular velocity of Gear B, as the gear ratio determines the trade-off between speed and torque.
The mechanical advantage is the ratio of output force to input force, indicating how many times the input force is multiplied. Complex machines combine two or more simple machines, often involving multiple gears to achieve a specific mechanical advantage or efficiency, which is the ratio of output work to input work.