19. An electromagnetic wave in vacuum has the electric field E = E₀cos(ωt - kx)x, where ω = ck. What is the magnetic field?
(A) B = sin(ωt - kx)y.
(B) B =CE₀sin(ωt + kz)z.
(C) B =cos(ωt - kx)z.
(D) B = cE₀cos(ωt + kz)z.
(E) B =cE₀sin(ωt - kx)y.

15. What happens in the limit t → ∞?(A)VC = 0, IL = 0. (B) VC = 0, IL = V0/R2. (C) VC = V0/R1, IL = 0.(D) VC = V0, IL = 0.(E)VC = V0, IL = V0/R2.

16. Which statement below is correct?(A) Two capacitors C1, C2 in parallel is equivalent to the capacitance of (C1-1+ C2-1), (B)The potential energy of a capacitorC at potential difference V equals CV2, (C) Maxwell’s equations imply charge conservation,(D) Maxwell’s equations imply the Lorentz force law. (E) The (volume) energy density for a magnetic field B in vacuum is

17. A background of magnetic field B(x, y) =(a + by)x is prepared on the x-y plane for given constants a and b. A rectangular loop (see figure) moves at a constant velocity v. The bottom of the loop coincides with the x axis, and its left side is at x = 0 when t = 0. What is the induced emf on the loop at time t? (z direction points out of plane.)(A) (a + bh)Lv clockwise. (B) (a + bh)Lv counter-clockwise. (C) (ah + bh2/2)Lv clockwise. (D) (ah + bh2/2)Lv counter-clockwise. (E) 0.

18. Which statement below is correct? (A) A point charge at constant velocity radiates due to Lorentz contraction. (B) A point charge in free fall in a gravitational field feels no back-reaction force. (C) A point charge in free fall does not radiate. (D) A radiation in an inertial frame may appear like vacuum in another inertial frame. (E) The energy radiated from an accelerating point charge per unit time is the same in every inertial frame.

20. Which statement below is correct? (A) In the double-slit experiment, it would be easier to see the double-slit interference pattern if the width of the slits is larger than the distance between the slits. (B) Electromagnetic plan waves have 3 independent polarizations. (C) The sky is blue because it reflects the image of the sea. (D) For a small spherical mirror of radius R, its focus is R/2. (E) The rainbow appears in the direction of the sun.

1. Which statement is wrong for fungi and fungal diseases? (A) Ascomycota includes molds and yeasts. (B) Aspergillus species can cause aspergillosis and their main portal of entry to the host is the gastrointestinal tract. (C) Candida albicans is a member of the human normal microbiota, but can cause different diseases in immunocompromised individuals. (D) Basidiomycota includes many common mushrooms. (E) Zygomycetes are commonly used in pharmaceutical and food manufacturing.

2. Choose the wrong one from the following statements about bacteria. (A) In alpha-hemolysis, a green zone (incomplete hemolysis) was observed around a bacterial colony on blood agar. (B) Purple sulfur bacteria oxidize hydrogen sulfide to sulfur and are usually photolithoautotrophs. (C) Methylotrophs are proteobacteria that use one-carbon compounds as carbon and energy sources. (D) Nitrifying bacteria can oxidize either ammonium to nitrite or nitrate. (E) Members of the Staphylococcus genus are Gram-negative aerobic bacteria.

3. Please choose the correct statement from comparison among Bacteria, Archaea and Eukarya. (A) Both Archaea and Eukarya contain membrane-enclosed nucleus with nucleolus. (B) Gas vesicles are present in Eukarya, but not in Bacteria and Archaea. (C) Chemolithotrophy is only present in Bacteria, but is absent in Archaea and Eukarya. (D) Bacteria are sensitive to rifampicin, but Archaea are insensitive to rifampicin. (E) The cell wall of Bacteria and Archaea contain muramic acid, which is absent in Eukarya cell wall.

4. Which is correct regarding bacterial infections and diseases? (A) Yersinia pestis is a Gram-positive bacterium to cause plague. (B) Toxoid is used to describe the condition caused by bacterial toxins in the blood of the host. (C) Legionnaires' disease is caused by bacteria transmitted by arthropods. (D) Enterotoxic E.coli (ETEC) can penetrate and multiply within the intestinal epithelial cells to cause diarrhea. (E) Botulism is caused by ingesting the botulinum AB neurotoxin, not bacterial cells.

5. Choose a correct statement related to antimicrobial chemotherapy. (A) Fluoroquinolones block bacterial DNA replication, by inhibiting DNA gyrase and topoisomerase II. (B) Tetracyclines are antibacterial drugs that can inhibit the synthesis of peptidoglycans, the important component of bacterial cell wall. (C) Penicillins are bactericidal by inhibiting bacterial cell membrane synthesis. (D) Cephalosporins are a class of beta-lactam antibiotics and can disrupt bacterial protein synthese. (E) The Bradford assay is commonly used to measure antimicrobial activity of an antibacterial drug.