81. Statement 1(S1): Luminol test is a confirmatory test for detection of blood.
Statement 2 (S2): Luminol added together with H2O2 (Hydrogen Peroxide) becomes luminescent in the presence of haemoglobin.
Choose the correct answer:
A. S1 and S2 both are correct and S2 is explanation of S1
B. S1 and S2 both are correct and S2 is not correct explanation of S1
C. S1 is false and S2 are true
D. Both are false
Ans.- C. S1 is false and S2 are true
Explanation:
Luminol Test is a Presumptive Test for Blood detection. The luminol solution contains both luminol (C8H7N3O2) and hydrogen peroxide (H2O2). The hydrogen peroxide reacts with the iron in blood to produce oxygen, then oxygen then reacts with the luminol, changing the structure of the molecule and temporarily adding energy, which produce light.
82. ‘Disulfiram’ is used for treatment of chronic alcohol abuse acts by:
i. Increasing the concentration of acetaldehyde
ii. Blocking aldehyde dehydrogenase
iii. Increasing the concentration of acetic acid
iv. Blocking acetate dehydrogenase Choose the correct answer
| A. iii and iv | B. i and iv |
| C. i and ii | D. ii and iii |
Ans.- C. i and ii
Explanation:
The enzyme alcohol dehydrogenase in the liver and brain converts alcohol into acetaldehyde. The enzyme aldehyde dehydrogenase (ALDH) oxidizes the acetaldehyde byproduct into acetic acid. Disulfiram inhibits this oxidation by inhibiting ALDH, causing rapid development of acetaldehyde in the blood upon consumption of alcohol. The result is called the disulfiram – alcohol reaction, and it can increase the concentration of acetaldehyde in the blood by 5 to 10 times that occurring without disulfiram.
83. The net retardation of projectile due to air resistance is given by:
| A. AVn | B. ½ gt2 |
| C. t xV cos E | D. |
Where ‘A’ and ‘n’ are constant that vary for different velocity zones ,’V’ is the velocity of the projectile , ‘g’ is the acceleration due to gravity , ‘t’ is the time taken by projectile, ‘E’ is the angle of deviation and ‘r’ the ogival radius in calibers.
Ans.- A. AVn
84. Which type of neutron is most suitable for NAA technique?
| A. Very low energy neutron | B. Cold neutron |
| C. Thermal neutron | D. High energy neutron |
Ans.- C. Thermal neutron
85. Match List-1 with List2
| List-1 | List-2 |
| a. RFLP | i. Heteroplasmy |
| b. STR | ii. Southern blotting |
| c. mt-DNA | iii. Paternal lineage |
| d. Y-STR | iv. Multiplexing |
Choose the correct option from those given below:
| A. | a- iv | b- i | c- ii | d- iii |
| B. | a- i | b- iii | c – iv | d- ii |
| C. | a. ii | b- iv | c- i | d- iii |
| D. | a. iii | b- ii | c- iv | d- i |
Ans.- C.
86. ANFO stands for:
| A. Ammonium Nitrite Fuel Oil | B. Ammonium Nitrate Fuel Oil |
| C. Ammonium Nitride Fuel Oil | D. Ammonium Nitroglycerine Fuel Oil |
Ans.- B. Ammonium Nitrate Fuel Oil
87. Aluminum, calcium, magnesium and cobalt are components of:
| A. Red colour safety glass | B. Blue colour safety glass |
| C. Yellow colour safety glass | D. Green colour safety glass |
Ans.- B. Blue colour safety glass
88. Statement 1 (S1):- Cement is made by mixing together calcareous and argillaceous material at high temperature.
Statement 2 (S2):- Property of cement depends on various phase composition of clinker and on the structure of individual crystal phase.
Choose the correct answer:
| A. Both are Correct | B. Both are wrong |
| C. S1 correct, S2 wrong | D. S1 wrong, S2 correct |
Ans.- A. Both are Correct
89. Which of the following is used to analyze for the presence of ‘Gun-Shot-Residue’?
| A. Micro spectrophotometry | B. Refractive Index measurement |
| C. Polarized light Microscopy | D. Scanning Electron Microscopy coupled with energy dispersive X-ray analyzer |
Ans.- D. Scanning Electron Microscopy coupled with energy dispersive X-ray analyzer
Explaining:
Scanning electron microscopes can observe individual characteristics of each particle. This can link lead (Pb), barium (Ba), and antimony (Sb) to a single particle, which can determine if the elements are unique or consistent with gunshot residue.
90. In trap cases, the pink colour of ‘Phenolphthalein’ fades due to:
| A. Complex with Na2CO3 | B. 2 (4-hydroxybenzoyle) benzoic acid and phenol |
| C. Trichlorophenolphthalein | D. Phenolic anhydride |
Ans.- B. 2 (4-hydroxybenzoyle) benzoic acid and phenol
Explanation:
Colour of phenolphthalein fades due to its breaking down into 2 (4-hydroxybenzoyl) benzoic acid and phenol in alkali medium. The chemical break down of the alkaline phenolphthalein is caused by the oxygen present in the air.
