Principles of Engineering (POE) - PLTW - Core Concepts: Statics, Materials, Mechanisms,
Electrical, Fluid Power, Thermodynamics, Systems, & Design
1. In the PLTW Principles of Engineering course, what is the primary definition of
"Engineering"?
A) The art of building structures
B) The application of mathematics and scientific principles to better or improve life
C) The process of fixing broken machines
D) The study of computer programming
Answer: B) Engineering is defined as the application of mathematics and scientific principles
to discover new technologies and improve the quality of life for people.
2. What is the standard unit of work and energy in the SI system?
A) Watt
B) Newton
C) Joule
D) Pascal
Answer: C) The Joule (J) is the SI derived unit of energy, work, and heat. One joule is the work
done by a force of one newton acting over a distance of one meter.
3. A force of 50 N is applied to a box at an angle of 30° above the horizontal to move it 5
meters. What is the work done?
A) 250 J
B) 216.5 J
C) 125 J
D) 0 J
Answer: B) Work = Force × Distance × cos(θ). W = (50 N)(5 m)(cos 30°) = 250 × 0.866 = 216.5 J.
Only the horizontal component of the force does work.
4. What is the mechanical advantage of a simple machine defined as?
A) The ratio of input distance to output distance
B) The ratio of output force to input force
C) The ratio of output work to input work
D) The ratio of input power to output power
Answer: B) Mechanical advantage (MA) is the ratio of the output force (resistance force) to
the input force (effort force): MA = F_out / F_in. It tells how much a machine multiplies force.
5. What is the Ideal Mechanical Advantage (IMA) of a lever based on?
A) The ratio of the load force to the effort force
B) The ratio of the effort arm length to the load arm length
,C) The efficiency of the lever
D) The weight of the lever
Answer: B) For a lever, the ideal mechanical advantage is the ratio of the distance from the
fulcrum to the effort (effort arm) to the distance from the fulcrum to the load (resistance
arm). IMA = L_effort / L_load.
6. What type of simple machine is a ramp or inclined plane?
A) A wedge
B) A screw
C) An inclined plane
D) A pulley
Answer: C) An inclined plane is a flat supporting surface tilted at an angle, with one end
higher than the other, used to raise or lower a load. Ramps are inclined planes.
7. In the context of electrical circuits, Ohm's Law defines the relationship between:
A) Voltage, Current, and Power
B) Voltage, Current, and Resistance
C) Power, Current, and Resistance
D) Voltage, Power, and Resistance
Answer: B) Ohm's Law states: Voltage (V) = Current (I) × Resistance (R). It is the foundational
relationship in electrical circuit analysis.
8. A circuit has a 12-volt battery and a resistance of 4 ohms. What is the current flowing
through the circuit?
A) 48 A
B) 3 A
C) 8 A
D) 0.33 A
Answer: B) Using Ohm's Law: I = V/R. I = 12 V / 4 Ω = 3 A.
9. What is the power dissipated by a 10-ohm resistor carrying a 2-ampere current?
A) 5 W
B) 20 W
C) 40 W
D) 10 W
Answer: C) Using the power formula: P = I²R. P = (2 A)² × 10 Ω = 4 × 10 = 40 W.
10. What is the total resistance of the following series circuit: R1 = 10 Ω, R2 = 20 Ω, R3 = 30 Ω?
A) 60 Ω
B) 5.45 Ω
, C) 6000 Ω
D) 0.02 Ω
Answer: A) For resistors in series, the total resistance is the sum: R_total = R1 + R2 + R3 = 10 +
20 + 30 = 60 Ω.
11. What is the total resistance of the following parallel circuit: R1 = 10 Ω and R2 = 10 Ω?
A) 20 Ω
B) 5 Ω
C) 100 Ω
D) 0.1 Ω
Answer: B) For parallel resistors: 1/R_total = 1/R1 + 1/R2 = 1/10 + 1/10 = 2/10 = 1/5. So
R_total = 5 Ω. For two equal resistors, R_total = R/2.
12. In a parallel circuit, what electrical quantity is the same across each branch?
A) Current
B) Resistance
C) Voltage
D) Power
Answer: C) In a parallel circuit, the voltage is the same across all branches. The current divides
among the branches.
13. What is the definition of "Power" in a mechanical system?
A) Force times distance
B) Force times velocity
C) Mass times acceleration
D) Work times time
Answer: B) Power is the rate at which work is done. For a constant force, P = F × v (Force
multiplied by velocity). P = Work/Time.
14. One horsepower is approximately equal to how many watts?
A) 1000 W
B) 746 W
C) 550 W
D) 33,000 W
Answer: B) 1 Horsepower (hp) is defined as 550 ft·lb/s, which is approximately equal to 746
Watts.
15. A motor lifts a 100 kg mass at a constant speed of 2 m/s. What is the power output of the
motor? (g = 9.81 m/s²)
A) 1962 W
Electrical, Fluid Power, Thermodynamics, Systems, & Design
1. In the PLTW Principles of Engineering course, what is the primary definition of
"Engineering"?
A) The art of building structures
B) The application of mathematics and scientific principles to better or improve life
C) The process of fixing broken machines
D) The study of computer programming
Answer: B) Engineering is defined as the application of mathematics and scientific principles
to discover new technologies and improve the quality of life for people.
2. What is the standard unit of work and energy in the SI system?
A) Watt
B) Newton
C) Joule
D) Pascal
Answer: C) The Joule (J) is the SI derived unit of energy, work, and heat. One joule is the work
done by a force of one newton acting over a distance of one meter.
3. A force of 50 N is applied to a box at an angle of 30° above the horizontal to move it 5
meters. What is the work done?
A) 250 J
B) 216.5 J
C) 125 J
D) 0 J
Answer: B) Work = Force × Distance × cos(θ). W = (50 N)(5 m)(cos 30°) = 250 × 0.866 = 216.5 J.
Only the horizontal component of the force does work.
4. What is the mechanical advantage of a simple machine defined as?
A) The ratio of input distance to output distance
B) The ratio of output force to input force
C) The ratio of output work to input work
D) The ratio of input power to output power
Answer: B) Mechanical advantage (MA) is the ratio of the output force (resistance force) to
the input force (effort force): MA = F_out / F_in. It tells how much a machine multiplies force.
5. What is the Ideal Mechanical Advantage (IMA) of a lever based on?
A) The ratio of the load force to the effort force
B) The ratio of the effort arm length to the load arm length
,C) The efficiency of the lever
D) The weight of the lever
Answer: B) For a lever, the ideal mechanical advantage is the ratio of the distance from the
fulcrum to the effort (effort arm) to the distance from the fulcrum to the load (resistance
arm). IMA = L_effort / L_load.
6. What type of simple machine is a ramp or inclined plane?
A) A wedge
B) A screw
C) An inclined plane
D) A pulley
Answer: C) An inclined plane is a flat supporting surface tilted at an angle, with one end
higher than the other, used to raise or lower a load. Ramps are inclined planes.
7. In the context of electrical circuits, Ohm's Law defines the relationship between:
A) Voltage, Current, and Power
B) Voltage, Current, and Resistance
C) Power, Current, and Resistance
D) Voltage, Power, and Resistance
Answer: B) Ohm's Law states: Voltage (V) = Current (I) × Resistance (R). It is the foundational
relationship in electrical circuit analysis.
8. A circuit has a 12-volt battery and a resistance of 4 ohms. What is the current flowing
through the circuit?
A) 48 A
B) 3 A
C) 8 A
D) 0.33 A
Answer: B) Using Ohm's Law: I = V/R. I = 12 V / 4 Ω = 3 A.
9. What is the power dissipated by a 10-ohm resistor carrying a 2-ampere current?
A) 5 W
B) 20 W
C) 40 W
D) 10 W
Answer: C) Using the power formula: P = I²R. P = (2 A)² × 10 Ω = 4 × 10 = 40 W.
10. What is the total resistance of the following series circuit: R1 = 10 Ω, R2 = 20 Ω, R3 = 30 Ω?
A) 60 Ω
B) 5.45 Ω
, C) 6000 Ω
D) 0.02 Ω
Answer: A) For resistors in series, the total resistance is the sum: R_total = R1 + R2 + R3 = 10 +
20 + 30 = 60 Ω.
11. What is the total resistance of the following parallel circuit: R1 = 10 Ω and R2 = 10 Ω?
A) 20 Ω
B) 5 Ω
C) 100 Ω
D) 0.1 Ω
Answer: B) For parallel resistors: 1/R_total = 1/R1 + 1/R2 = 1/10 + 1/10 = 2/10 = 1/5. So
R_total = 5 Ω. For two equal resistors, R_total = R/2.
12. In a parallel circuit, what electrical quantity is the same across each branch?
A) Current
B) Resistance
C) Voltage
D) Power
Answer: C) In a parallel circuit, the voltage is the same across all branches. The current divides
among the branches.
13. What is the definition of "Power" in a mechanical system?
A) Force times distance
B) Force times velocity
C) Mass times acceleration
D) Work times time
Answer: B) Power is the rate at which work is done. For a constant force, P = F × v (Force
multiplied by velocity). P = Work/Time.
14. One horsepower is approximately equal to how many watts?
A) 1000 W
B) 746 W
C) 550 W
D) 33,000 W
Answer: B) 1 Horsepower (hp) is defined as 550 ft·lb/s, which is approximately equal to 746
Watts.
15. A motor lifts a 100 kg mass at a constant speed of 2 m/s. What is the power output of the
motor? (g = 9.81 m/s²)
A) 1962 W
