#1
Which of the following devices converts mechanical energy into electrical energy?
Generator
ExplanationGenerators convert mechanical energy, often from rotating turbines, into electrical energy through electromagnetic induction.
#2
Which of the following statements regarding friction is true?
Friction always opposes the motion of an object.
ExplanationFriction acts opposite to the direction of an object's motion, impeding its movement.
#3
Which of the following is NOT a type of lever?
Fourth-class lever
ExplanationFourth-class levers do not exist; levers are classified into three types based on the relative positions of fulcrum, effort, and load.
#4
Which of the following is NOT a type of simple machine?
Gear
ExplanationGears are not considered simple machines; they are components often used within machines to transmit motion or change speed/direction.
#5
What is the SI unit of torque?
Newton-meter
ExplanationTorque, a measure of rotational force, is measured in newton-meters in the International System of Units (SI).
#6
Which of the following best describes Pascal's law?
Pressure applied to a confined fluid is transmitted undiminished to every point of the fluid and to the walls of its container.
ExplanationFluid pressure remains constant throughout a closed system, regardless of the container's shape.
#7
What is the principle behind the operation of a hydraulic jack?
Pascal's law
ExplanationHydraulic jacks operate on the principle of Pascal's law, where pressure applied to a confined fluid is transmitted uniformly.
#8
What is the formula for calculating mechanical advantage in a simple machine?
Output force / Input force
ExplanationMechanical advantage in a simple machine is the ratio of the output force to the input force.
#9
What is the principle behind the functioning of a gear train?
Law of torque
ExplanationGear trains operate based on the principle of torque transmission, ensuring force multiplication or speed reduction.
#10
What does Hooke's law describe?
The restoring force exerted by a spring when it is stretched or compressed.
ExplanationHooke's law describes the relationship between the force exerted on a spring and the resulting deformation, stating it's directly proportional.
#11
What does the term 'moment of inertia' refer to in mechanics?
The tendency of a body to resist angular acceleration.
ExplanationMoment of inertia quantifies a body's resistance to changes in its rotational motion.