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Explain any two of the following: Variable resistor, Rack and pinion, Compressive force, Hand vice. - Leaving Cert Engineering - Question 1 - 2013
Question 1
Explain any two of the following: Variable resistor, Rack and pinion, Compressive force, Hand vice.
Worked Solution & Example Answer:Explain any two of the following: Variable resistor, Rack and pinion, Compressive force, Hand vice. - Leaving Cert Engineering - Question 1 - 2013
Step 1
Variable resistor
Answer
A variable resistor is an electrical component that allows for the adjustment of resistance within a circuit. It consists of a resistive element and a movable contact (wiper) that slides across the element. The resistance can be varied by turning a spindle, which changes the position of the wiper between the two terminals. This can adjust the flow of current in the circuit, making it essential for applications such as dimmers in lighting or as part of sensor circuits. Additionally, other components like Light Dependent Resistors (LDR) or Thermistors can also function as variable resistors depending on external conditions such as light intensity or temperature.
Step 2
Rack and pinion
Answer
The rack and pinion mechanism is a system used to convert rotary motion into linear motion or vice versa. It consists of a gear (the pinion) that engages with a flat toothed bar (the rack). When the pinion rotates, it moves the rack linearly. This is commonly seen in steering systems and drilling machines. In a drilling context, the rotation of the drill handle causes the pinion to rotate, moving the rack and consequently pushing the drill bit downward in a straight line. This mechanism is valuable in applications where precise linear movement is required.