Q1: Function of gear box is to

ANS:B - obtain variable speed.

Obtaining variable speed refers to the ability of a gearbox or transmission system to allow for a range of output speeds, rather than a fixed reduction or increase in speed. This variability can be achieved through various mechanisms within the gearbox design. Here's how it works:

1. Variable Gear Ratios: Some gearboxes incorporate mechanisms such as planetary gear sets, continuously variable transmissions (CVTs), or adjustable gear arrangements that can change the gear ratio between the input and output shafts. By altering the gear ratio, the gearbox can provide a continuously adjustable range of output speeds.
2. Adjustable Input Speed: In some systems, the input speed to the gearbox can be varied, which consequently affects the output speed. This can be achieved through mechanisms like adjustable pulleys, hydraulic systems, or electronic control systems that regulate the speed of the input shaft.
3. Electronic Control: Modern gearboxes may incorporate electronic control systems that adjust the gear ratio or input speed based on various factors such as load conditions, vehicle speed, or driver inputs. These systems can optimize the output speed for efficiency, performance, or specific operational requirements.
4. Hydraulic Systems: In certain applications, hydraulic systems can be used to control the output speed by adjusting the flow of hydraulic fluid to hydraulic motors or actuators connected to the gearbox. This method allows for precise control of speed in hydraulic machinery.

Overall, obtaining variable speed through a gearbox involves implementing mechanisms that allow for continuous adjustment of the output speed within a specified range, providing flexibility and adaptability to meet the requirements of different tasks or operating conditions.