Selected MCQ

Current Question
A Carnot engine operating between 500 K and 300 K has maximum efficiency:
  • A. 20%
  • B. 40%
  • C. 60%
  • D. 80%
Correct Answer: B
Explanation:
Carnot efficiency is (1-\frac{T_c}{T_h}=1-\frac{300}{500}=0.40).
Related Question 1
Which force acts between charges?
  • A. Gravitational
  • B. Magnetic
  • C. Electric
  • D. Nuclear
Correct Answer: C
Explanation:
Electric force acts on charges.
Related Question 2
In quantum electrodynamics, the interaction between charged particles is mediated by:
  • A. Gluons
  • B. Photons
  • C. Gravitons
  • D. W bosons
Correct Answer: B
Explanation:
Electromagnetic interactions occur via exchange of virtual photons.
Related Question 3
Which force acts between masses?
  • A. Electric
  • B. Magnetic
  • C. Gravitational
  • D. Nuclear
Correct Answer: C
Explanation:
Gravity acts on mass.
Related Question 4
Which system has maximum entropy?
  • A. Perfect crystal at 0 K
  • B. Completely random system
  • C. Ideal gas at absolute zero
  • D. Vacuum
Correct Answer: B
Explanation:
Maximum disorder corresponds to maximum entropy.
Related Question 5
Which level of protein structure is most directly stabilized by hydrogen bonds between backbone groups?
  • A. Primary
  • B. Secondary
  • C. Tertiary only
  • D. Quaternary only
Correct Answer: B
Explanation:
(\alpha)-helices and (\beta)-sheets arise from backbone hydrogen bonding patterns.