ASVAB (Armed Services Vocational Aptitude Battery)Mechanical Comprehension (MC)Medium
An electrician is using a screwdriver to turn a screw. The screwdriver's handle has a larger diameter than its shaft. This setup functions as which type of simple machine?
- AWedge
- BWheel and Axle
- CLever
- DInclined Plane
Show answer & explanationAnswer & explanation
Correct answer: B. Wheel and Axle
A screwdriver functions as a wheel and axle. The handle acts as the 'wheel' (larger radius where effort is applied), and the shaft/screw acts as the 'axle' (smaller radius where the load is moved). This provides a mechanical advantage by converting a small force applied over a large distance (handle rotation) into a larger force applied over a smaller distance (screw rotation).
Why the other options are wrong
- A. A wedge is used to split or separate, which is not the primary function of a screwdriver.
- C. While a lever involves rotation, a screwdriver's primary mechanism is a wheel and axle, not a lever.
- D. An inclined plane is a flat surface set at an angle, not representative of a screwdriver's operation.
Wheel and Axle
A simple machine consisting of a wheel attached to a smaller axle, both rotating around the same axis. It provides mechanical advantage by applying force to the larger wheel to turn the smaller axle.
- Effort applied to the wheel, load resistance on the axle.
- Mechanical advantage = Radius of Wheel / Radius of Axle.
- Examples: doorknobs, steering wheels, screwdrivers.
Memory trick: LIPS W-W: Lever, Inclined Plane, Pulley, Screw, Wedge, Wheel & Axle.