Chains of Energy Conversion

Science and Technology · 10 questions

Explore energy conversions in generators, batteries, heat pumps, and engines.

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1. In a generator, what type of energy does mechanical energy become?

   1. Chemical energy
   2. Thermal energy
   3. Electrical energy
   4. Nuclear energy
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   C) Electrical energy

2. Which category includes battery cells that can be recharged?

   1. Secondary cells
   2. Fuel cells
   3. Primary cells
   4. Photovoltaic cells
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   A) Secondary cells

3. In heating mode, how is a heat pump's COP calculated?

   1. Heat delivered / electrical energy used
   2. Electrical energy used / heat delivered
   3. Heat extracted / heat delivered
   4. Heat delivered / ambient temperature
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   A) Heat delivered / electrical energy used

4. What is the main useful energy output of a running internal combustion engine?

   1. Nuclear energy
   2. Chemical energy
   3. Electrical energy
   4. Mechanical energy
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   D) Mechanical energy

5. With its pole count fixed, how does a synchronous generator's output frequency change as rotor speed rises?

   1. A lower frequency
   2. The same frequency
   3. Zero frequency
   4. A higher frequency
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   D) A higher frequency

6. Which unit is commonly used to express battery capacity?

   1. Ohm
   2. Watt
   3. Ampere-hour
   4. Volt
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   C) Ampere-hour

7. What energy transfer occurs in the refrigerant in a heat pump's evaporator?

   1. Chemical energy storage
   2. Heat absorption
   3. Electricity generation
   4. Heat release
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   B) Heat absorption

8. In a diesel engine, what primarily ignites the injected fuel?

   1. Air heated by compression
   2. A spark plug
   3. An electric arc
   4. Refrigerant pressure
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   A) Air heated by compression

9. Two identical 1.5 V cells are connected in series with their polarities aligned so their voltages add. What is their total nominal voltage?

   1. 0.75 V
   2. 6 V
   3. 3 V
   4. 1.5 V
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   C) 3 V

10. In a simple DC generator, what is the commutator's main function?

    1. Alternating current in the external circuit
    2. One-way current in the external circuit
    3. Magnetic-field generation
    4. Mechanical rotor rotation
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    B) One-way current in the external circuit