When considering the conduction of electricity, the term cathode refers to
a) a positive wire.
b) a neutral aqueous solution.
c) a melted ionic compound.
d) a negative wire.
d
You might also like to view...
What is Charon?
A) Pluto's largest moon B) the largest known asteroid C) the largest known comet D) one of the Galilean moons of Jupiter E) a moon of Neptune
An electronic device is cooled by passing air at 27°C through six small tubular passages in parallel drilled through the bottom of the device in parallel as shown. The mass flow rate per tube is 7 × 10–5 kg/s. Heat is generated in the device resulting in approximately uniform heat flux to the air in the cooling passage. To determine the heat flux, the air outlet temperature is measured and found to be 77°C. Calculate the rate of heat generation, the average heat transfer coefficient, and the surface temperature of the cooling channel at the center and at the outlet.
GIVEN
• Air flow through small tubular passages as shown above
• Air temperature
? Entrance (Tb,in) = 27°C
? Exit (Tb,out) = 77°C
• Mass flow rate per passage (m )= 7 × 10–5 kg/s
• Number of passages (N) = 6
FIND
(a) The rate of heat generation ( Q
G) (b) The average heat transfer coefficient ( h c) (c) Cooling channel surface temperature at the center (Ts,c) (d) Cooling channel surface temperature at the outlet (Ts,out)
ASSUMPTIONS
• Steady state
• Uniform heat generation
• Uniform heat flux to the air
• Viscosity variation is negligible
• Heat transfer coefficient is approximately constant axially
PROPERTIES AND CONSTANTS
for dry air at the average bulk temperature of 52°C
Specific heat (c) = 1016 J/(kg K) ]
Thermal conductivity (k) = 0.0273 W/(m K)
Absolute viscosity (?) = 19.593 × 10–6 (Ns)/m2
Prandtl number (Pr) = 0.71
Discuss why it is impossible for a particle to decay into a single particle of less mass
What will be an ideal response?
An astronaut's normal weight it 600 newtons. How much will she weigh while orbiting in a satellite at 12,000 kilometers [two earth radii] above the surface of Earth?
A) zero B) 300 newtons C) 200 newtons D) 67 newtons E) 150 newtons