The cosmic background radiation
a. has a blackbody spectrum
b. has its peak emission in the microwave band
c. corresponds to a blackbody at a temperature of 2.726 kelvins
d. all of the above
A
You might also like to view...
A 100 kg mass is blown apart into a 60 kg piece and a 40 kg piece. After the blast, the two masses are moving apart with a relative velocity of 60 m/s. The velocity of the 60 kg mass is
A. 88 m/s. B. 67 m/s. C. 51 m/s. D. 40 m/s. E. 24 m/s.
A venturi tube may be used as the inlet to an automobile carburetor. If the 2.0-cm diameter pipe narrows to a 1.0-cm diameter, what is the pressure drop in the constricted section for an airflow of 3.0 m/s in the 2.0-cm section? (? = 1.2 kg/m3.)
a. 70 Pa b. 85 Pa c. 100 Pa d. 120 Pa e. 81 Pa
Displacement is which of the following types of quantities?
a. vector c. magnitude b. scalar d. dimensional
What is expression gives the efficiency of an ideal heat engine operating between a higher temperature Th and a lower temperature Tc (both expressed in kelvins)?
a. = 1 + Tc / Th b. = 1 – Tc / Th c. = 1 – Th / Tc d. = 1 – Tc e. = Tc / Th