Which sequence of events is in the correct chronological order?
A. Quarks form, protons form, protons and electrons recombine into atoms, helium is produced.
B. Protons form, helium is produced, protons and electrons recombine into atoms, quarks form.
C. Protons form, quarks form, protons and electrons recombine into atoms, helium is produced.
D. Quarks form, protons form, helium is produced, protons and electrons recombine into atoms.
Answer: D
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The stage II creep rate in metals and ceramics at constant stress and temperature is
(a) Transient and decreasing. (b) Increasing toward rupture. (c) A constant. (d) Parabolic.
A contact lens is made of plastic with an index of refraction 1.50 . The lens has an outer radius of curvature of + 1.65 cm and an inner radius of curvature of + 5.85 cm. What is its focal length?
a. –4.60 cm b. +1.53 cm c. +2.57 cm d. +4.60 cm e. –2.57 cm
A grating with 396 lines/mm is illuminated with light of wavelength 343 nm. What is the angular separation between the two second-order bright fringes?
A) 31.5° B) 15.8° C) 32.9°
A Carnot engine
A. consists of zero heat flow and constant pressure processes. B. consists of only processes which do not involve heat flow. C. consists of only isothermal processes. D. absorbs heat at a single high temperature and rejects heat at a single low temperature. E. consists of constant temperature and constant volume processes.