Energy transfer and transformation Knowledge-Based Practice

Questions

1. 1.

   During any real-world energy transformation, why is the useful energy output of a machine always less than the total energy input?

   • A) A fraction of the total energy is permanently destroyed by resistive forces.
   • B) The total energy of the system decreases whenever mechanical work is performed.
   • C) A portion of the input energy is converted into matter during mechanical interactions.
   • D) A portion of the input energy is inevitably dissipated into thermal energy transferred to the surroundings.
2. 2.

   Which of the following processes represents an energy transfer rather than an energy transformation?

   • A) A candle burning to emit light and heat into a room
   • B) A wind turbine rotating to generate electric power
   • C) A toaster element heating up as electrical current passes through it
   • D) Heat conducting from a hot mug into a person's cold hands
3. 3.

   Which of the following statements correctly identifies the primary energy transformation that occurs during photosynthesis in green plants?

   • A) Thermal energy is transformed into chemical potential energy.
   • B) Chemical potential energy is transformed into radiant energy.
   • C) Radiant energy is transformed into chemical potential energy.
   • D) Radiant energy is transformed into kinetic energy.
4. 4.

   Which of the following correctly describes the primary energy transformation occurring inside an electrochemical battery while it discharges?

   • A) Electrical energy is transformed into chemical potential energy
   • B) Thermal energy is transformed into electrical energy
   • C) Chemical potential energy is transformed into electrical energy
   • D) Nuclear energy is transformed into electrical energy
5. 5.

   Which of the following statements correctly identifies the primary energy transformation that occurs inside an operating microphone?

   • A) Electrical energy is converted into sound energy.
   • B) Thermal energy is converted into electrical energy.
   • C) Sound energy is converted into electrical energy.
   • D) Radiant energy is converted into mechanical energy.
6. 6.

   A compressed steel spring is released to launch a block across a frictionless horizontal surface. Which of the following correctly identifies the primary energy transformation that occurs as the spring expands?

   • A) Gravitational potential energy is transformed into kinetic energy.
   • B) Kinetic energy is transformed into elastic potential energy.
   • C) Chemical potential energy is transformed into thermal energy.
   • D) Elastic potential energy is transformed into kinetic energy.
7. 7.

   Which of the following correctly identifies the primary energy transformation that occurs in an operating photovoltaic solar cell?

   • A) Radiant energy into electrical energy
   • B) Thermal energy into electrical energy
   • C) Chemical energy into electrical energy
   • D) Kinetic energy into electrical energy
8. 8.

   When a moving car applies its brakes and comes to a complete stop on a level road, which of the following describes the primary energy transformation that takes place?

   • A) Chemical energy is transformed into gravitational potential energy.
   • B) Thermal energy is transformed into kinetic energy.
   • C) Kinetic energy is transformed into thermal energy.
   • D) Gravitational potential energy is transformed into elastic potential energy.
9. 9.

   Which sequence correctly represents the primary energy transformations that occur in a hydroelectric power plant?

   • A) Gravitational potential energy $\rightarrow$ kinetic energy $\rightarrow$ electrical energy
   • B) Chemical potential energy $\rightarrow$ thermal energy $\rightarrow$ electrical energy
   • C) Kinetic energy $\rightarrow$ gravitational potential energy $\rightarrow$ electrical energy
   • D) Thermal energy $\rightarrow$ elastic potential energy $\rightarrow$ electrical energy
10. 10.

    Which of the following statements correctly identifies the primary energy transformation occurring in an operating electric motor?

    • A) Kinetic energy is transformed into electrical energy.
    • B) Electrical energy is transformed into chemical energy.
    • C) Chemical energy is transformed into electrical energy.
    • D) Electrical energy is transformed into kinetic energy.

Answers and step-by-step solutions appear after you finish the test.