Mechanical Comprehension Questions and Answers Flashcards
6 cards from real SIFT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Mechanical Comprehension Questions and Answers flashcards as text
If a wheel with radius 3 feet is connected to an axle with radius 1 foot, what is the mechanical advantage?
Answer: 3
The wheel and axle mechanical advantage = radius of wheel / radius of axle = 3/1 = 3. Turning the wheel requires less force than turning the axle directly.
What happens to the speed of a fluid when it flows from a wider pipe into a narrower pipe (Bernoulli's principle)?
Answer: Speed increases and pressure decreases
By the continuity equation and Bernoulli's principle, fluid speed increases as it flows into a narrower section, and pressure decreases correspondingly.
In a series electrical circuit with two resistors of 4Ω and 6Ω connected to a 20V battery, what is the total current?
Answer: 2 A
In a series circuit, total resistance = R₁ + R₂ = 4 + 6 = 10Ω. Current I = V/R = 20/10 = 2 A.
What does a 'shear pin' do in a mechanical system?
Answer: Intentionally breaks under excessive load to protect more expensive components
A shear pin is a deliberately weak fastener designed to break (shear) at a predetermined force, protecting more critical and expensive components from overload damage.
A ramp (inclined plane) is 10 feet long and 2 feet high. What is the mechanical advantage?
Answer: 5
Mechanical advantage of an inclined plane = length of slope / height = 10 / 2 = 5. You need only 1/5 the force to push an object up the ramp as you would to lift it straight up.
What is the primary function of a flywheel in a mechanical system?
Answer: To store rotational kinetic energy and smooth out speed fluctuations
A flywheel stores rotational kinetic energy due to its mass and rotational speed, smoothing out power delivery by releasing energy during low-power phases of a cycle.