energy transfer and conversion

Question 1

What factor primarily determines the speed of sound in a material?

a. Frequency of the wave
b. Temperature of the air
c. Density and elasticity of the medium
d. The loudness of the sound

Answer 1

c. Density and elasticity of the medium

Question 2

What is a major difference between conduction and convection as modes of heat transfer?

a. Convection involves bulk movement of particles
b. Conduction requires a vacuum
c. Conduction is slower than convection
d. Convection only happens in solids

Answer 2

a. Convection involves bulk movement of particles

Question 3

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

a. Heat from a stove warming a pot
b. Heat conducted from your hand to a cold object
c. Sound echo bouncing off a wall
d. Light energy converted to chemical energy during photosynthesis

Answer 3

d. Light energy converted to chemical energy during photosynthesis

Question 4

In a hydrogen fuel cell, what energy transformation takes place?

a. Thermal to chemical
b. Mechanical to chemical
c. Chemical to electrical
d. Electrical to light

Answer 4

c. Chemical to electrical

Question 5

Why does the pitch of an ambulance siren appear to decrease after it passes you?

a. The amplitude drops
b. The frequency decreases as the source moves away
c. The medium changes
d. Your hearing adapts

Answer 5

b. The frequency decreases as the source moves away

Question 6

Which characteristic of a material most affects its thermal conductivity?

a. Color
b. Density
c. Atomic structure and free electrons
d. Shape

Answer 6

c. Atomic structure and free electrons

Question 7

A photovoltaic cell primarily converts which form of energy?

a. Thermal to chemical
b. Electromagnetic to electrical
c. Mechanical to electrical
d. Nuclear to mechanical

Answer 7

b. Electromagnetic to electrical

Question 8

In terms of energy transformation, what sequence best describes hydroelectric power generation?

a. Chemical → Electrical → Kinetic
b. Gravitational → Kinetic → Mechanical → Electrical
c. Electrical → Kinetic → Potential
d. Solar → Mechanical → Electrical

Answer 8

b. Gravitational → Kinetic → Mechanical → Electrical

Question 9

Which statement about nuclear fusion in the Sun is correct?

a. It splits heavy atoms into smaller ones
b. It converts kinetic energy into chemical energy
c. It fuses hydrogen atoms, releasing large amounts of energy
d. It is a type of radioactive decay

Answer 9

c. It fuses hydrogen atoms, releasing large amounts of energy

Question 10

In energy terms, what makes uranium-235 an efficient fuel source?

a. It is easy to mine
b. It has a high specific energy due to mass-energy conversion
c. It is renewable
d. It has low radioactive emissions

Answer 10

b. It has a high specific energy due to mass-energy conversion

Question 11

What process turns nuclear energy into usable electricity?

a. Solar absorption
b. Battery storage
c. Combustion
d. Steam turbine rotation

Answer 11

d. Steam turbine rotation

Question 12

What primarily drives the rate of thermal energy transfer?

a. Magnetic field
b. Air pressure
c. Temperature difference
d. Voltage difference

Answer 12

c. Temperature difference

Question 13

When did the emergence of man approximately occur?

a. 1318 A.D.
b. 950 A.D.
c. 5000 B.C.
d. 4,000,000 B.C.

Answer 13

d. 4,000,000 B.C.

Question 14

What directly affects wind energy conversion rate?

a. Solar intensity and blade color
b. Gas composition
c. Wind speed and air density
d. Heat and pressure

Answer 14

c. Wind speed and air density

Question 15

The modern steam engine was developed in:

a. 1712 A.D.
b. 1954 A.D.
c. 1765 A.D.
d. 1802 A.D.

Answer 15

c. 1765 A.D.

Question 16

What regulates the rate of nuclear energy conversion?

a. Electrical voltage
b. Wind speed
c. Fuel type
d. Number of reactions per second

Answer 16

d. Number of reactions per second

Question 17

What is the unit commonly used to measure the rate of electrical energy conversion?

a. Joule
b. Ampere
c. Watt
d. Volt

Answer 17

c. Watt

Question 18

When did the first nuclear power plant begin operation?

a. 1884 A.D.
b. 1765 A.D.
c. 1954 A.D.
d. 950 A.D.

Answer 18

c. 1954 A.D.

Question 19

The windmill was developed around which year?

a. 1318 A.D.
b. 1802 A.D.
c. 1712 A.D.
d. 950 A.D.

Answer 19

d. 950 A.D.

Question 20

Which property is not involved in thermal energy transfer?

a. Surface area
b. Sound frequency
c. Thermal conductivity
d. Material thickness

Answer 20

b. Sound frequency

Question 21

The development of human civilization is dated around:

a. 5000 B.C.
b. 350 A.D.
c. 1712 A.D.
d. 1954 A.D.

Answer 21

d. 5000 B.C.

Question 22

What component is not part of solar energy conversion rate?

a. Panel surface area
b. Solar panel efficiency
c. Fuel type
d. Sunlight intensity

Answer 22

c. Fuel type

Question 23

What major energy-related invention was developed around 350 A.D.?

a. Windmill
b. Steam engine
c. Water wheel
d. Cannon

Answer 23

c. Water wheel

Question 24

Hydropower conversion rate depends on water flow and:

a. Cloud thickness
b. Water color
c. Falling height
d. Air pressure

Answer 24

c. Falling height

Question 25

Which direction does heat always flow? a. From cold to hot b. From hot to cold c. From low pressure to high pressure d. From low energy to high energy

Answer 25

b. From hot to cold

Question 26

What is the primary heat transfer mechanism in metals? a. Radiation b. Conduction via free electrons c. Convection d. Diffusion

Answer 26

b. Conduction via free electrons

Question 27

What type of heat transfer occurs in boiling water causing fluid motion? a. Conduction b. Radiation c. Natural convection d. Forced convection

Answer 27

c. Natural convection

Question 28

Which heat transfer method becomes more significant at high temperatures? a. Conduction b. Convection c. Radiation d. Diffusion

Answer 28

c. Radiation

Question 29

Which of the following occurs fastest in turbulent flows? a. Molecular diffusion b. Radiation c. Eddy diffusion d. Conduction

Answer 29

c. Eddy diffusion

Question 30

What dimensionless number compares momentum and mass transfer? a. Reynolds number b. Prandtl number c. Nusselt number d. Schmidt number

Answer 30

d. Schmidt number

Question 31

Which type of energy transfer does lifting a book represent? a. Electrical work b. Radiative transfer c. Mechanical work d. Conduction

Answer 31

c. Mechanical work

Question 32

What energy conversion occurs when a battery powers a light bulb? a. Mechanical to thermal b. Electrical to thermal and light c. Thermal to chemical d. Gravitational to electrical

Answer 32

b. Electrical to thermal and light

Question 33

Which best describes work in a thermodynamic system? a. Change in pressure alone b. Random energy motion c. Energy transfer due to force and displacement d. Absorption of electromagnetic waves

Answer 33

c. Energy transfer due to force and displacement

Question 34

In a car engine, the movement of pistons is a result of: a. Work by expanding gases b. Heat radiation c. Convection d. Molecular diffusion

Answer 34

a. Work by expanding gases

Question 35

What happens during an exothermic chemical reaction? a. Energy is stored in products b. Temperature decreases c. Heat is absorbed d. Energy is released

Answer 35

d. Energy is released

Question 36

Which of the following is true of an endothermic reaction? a. Products have lower enthalpy b. Reaction releases energy c. Energy is absorbed from surroundings d. Heat is produced

Answer 36

c. Energy is absorbed from surroundings

Question 37

How does a catalyst speed up a chemical reaction? a. Increases temperature b. Decreases pressure c. Provides a lower activation energy pathway d. Adds more reactants

Answer 37

c. Provides a lower activation energy pathway

Question 38

Which of the following reactions is exothermic? a. Electrolysis b. Combustion c. Photosynthesis d. Decomposition

Answer 38

b. Combustion

Question 39

What determines the rate of a chemical reaction, according to the Arrhenius equation? a. Electrical current b. Enthalpy c. Temperature d. Pressure

Answer 39

c. Temperature

Question 40

Which part of a boundary layer mainly resists mass transfer? a. Turbulent core b. Velocity gradient zone c. Concentration boundary layer d. Radiative front

Answer 40

c. Concentration boundary layer