Heat Transfer ALL MULTIPLE CHOICE

thermal energy in transit due to a difference in temperature between two regions in space

molecular interactions

d

d

c

d

molecular interactions plus bulk (macroscopic) liquid motion

d

a

e

all of the above

the increase in energy stored equals the amount that enters minus the amount that leaves

c

thermal and mechanical energy can both be generated by chemical, electrical, electromagnetic, or nuclear energy processes

d

dimensions are physical quantities and units are measures of physical quantities

mass, length, time, temperature

a

a and c

independent of the coordinate direction

a and b

all of the above

b

a

b

d

an initial condition specifies the temperature at the start of the problem and a boundary condition provides information about temperatures on the boundaries

c

b

c

a and b

the temperature at the initial time throughout the domain

information about the temperature at one of the boundaries of the solid

all of the above

negative

positive

zero

2 to 1

1 to 2

Wall 2 has a higher conductivity than Wall 1

Wall 1 has a higher thermal conductivity than Wall 2

d

negative

there is heat flow into the wall

c

d

the thermal resistance of Wall B is twice that of Wall A

b

a

d

equal to q

the temperature gradients in wall will become larger

less than q

d

equals that of the outer surface

is greater than that from the outer surface

C

higher for larger diameter pipes

lower for larger diameter pipes

d

d

the fin has a uniform temperature equal to that of its base

d

increases

decreases

increases

increases

increases

decreases

true

used to compute the heat transfer for different situations

a

c

a

b

a

b

all the above

d

highest initially

the internal temperature of the object is uniform at all times

increase

decrease

increase

b

b and d

b

much less than unity

a and b

e

heat is being transferred in the negative x-direction

d

b

increase

b

d

all the above

region where velocity gradients are present

b

the velocity gradients normal to the flow direction are small