Reference no: EM132287941

Questions -

Question 1 - At what wavelength is the maximum radiative power emitted from an exhaust pipe at 650^oC?

Question 2 - Calculate the rate at which energy is radiated from a black surface, 0.3 m² in area, which is white hot at 1500^oC. The Stefan-Boltzmann constant is σ = 5.67 x 10^-8W m^-2 K⁴.

Question 3 - Calculate the surface temperature of a black surface, 1.6 m² in area if the rate of heat transfer is 632 kW. The Stefan-Boltzmann constant is σ = 5.67 x 10^-8 W m^-2 K⁴.

Question 4 - If we apply dimensional analysis to a forced convection heat transfer problem, what functional relationship between dimensionless groups do we obtain?

Question 5 - A copper pipe has thermal conductivity of 381 W m^-1 K^-1, 25 mm internal radius and 26 mm external radius is covered with a 12 mm layer of insulation of thermal conductivity 0.005 Wm^-1 K^-1. A diagram of the pipe and insulation is shown. If the inside wall temperature of the pipe is 220^oC and the outside temperature of the insulation is 10^oC, what is the heat loss per unit length of pipe?

Question 6 - 1800kJ of heat (Q) is transferred to 1 m³ of air at 14 bar and 200^oC. Find the final temperature and volume if the pressure remains constant.

Question 7 - 1kg of air at 1.02 bar, 20^oC is compressed reversibly according to the law pv^1.3= constant, to a pressure of 5.5bar and temperature of 432.7K. Calculate the work done (kJ kg^-1) on the air during the compression.

Question 8 - For an isentropic (adiabatic) process the specific work done is

R(T₂-T₁)/γ

u₂-u₁/γ

R(T₂-T₁)/(γ-1)

C_p(T₂-T₁)/γ

(h₂-h₁)/γ

Question 9 - The processes involved in a Diesel cycle are

Two constant volume, one constant pressure and one isentropic processes

One constant pressure, one constant volume and two isentropic processes

Two isothermal and two isentropic processes

Two constant pressure and two volume processes

Two constant pressure and two isothermal processes

Question 10 - A reciprocating compressor takes a charge of air at 1 bar and 20^oC and compresses it to 5 bar. Assuming that the compression is reversible and has an index, n, of 1.3, find the final temperature and heat per unit mass that must be extracted by a cooling jacket if the compressor is to run at a steady temperature.

T = 424.8 K, q = 62.8 kJ kg^-1

T = 151.8 K. q = 31.4 kJ kg^-1

T = 151.8 K, q = -31.4 kJ kg^-1

T = 424.8 K, q = 31.4 kJ kg^-1

T = 424.8 K, q= -31.4 kJ kg^-1