Daily Static MCQs for UPSC & State PSC Exams - Science and Technology (23 June 2023)

Daily Static MCQs Quiz for UPSC, IAS, UPPSC/UPPCS, MPPSC. BPSC, RPSC & All State PSC Exams

Subject : Science and Technology

1. Consider the following statements regarding Dry ice:

1. Dry ice is the solid form of carbon dioxide.
2. It has higher temperature than that of water ice.
3. It is used to prevent insect activity in closed containers of grains and grain products.

How many statements given above are correct?

(a) Only one
(b) Only two
(c) All three
(d) None

Answer: (B)

Explanation:

  • Dry ice is the solid form of carbon dioxide. It is used primarily as a cooling agent. Its advantages include lower temperature than that of water ice and not leaving any residue (other than incidental frost from moisture in the atmosphere). It is useful for preserving frozen foods where mechanical cooling is unavailable. Hence, statement 1 is correct while statement 2 is incorrect.
  • This extreme cold makes the solid dangerous to handle without protection due to burns caused by freezing (frostbite). While generally not very toxic, the outgassing from it can cause hypercapnia (abnormally elevated carbon dioxide levels in the blood) due to build-up in confined locations. Dry ice can be used to arrest and prevent insect activity in closed containers of grains and grain products, as it displaces oxygen, but does not alter the taste or quality of foods. For the same reason, it can prevent or retard food oils and fats from becoming rancid. When dry ice is placed in water, sublimation is accelerated, and low-sinking, dense clouds of smoke-like fog are created. This is used in fog machines, at theatres, haunted house attractions, and nightclubs for dramatic effects. One of the largest mechanical uses of dry ice is blast cleaning. Hence, statement 3 is correct.

2. Pneumoconiosis, sometimes seen in news is related to which of the following?

(a) High blood glucose levels
(b) Black lung disease
(c) Tuberculosis
(d) High levels of fat in the blood

Answer: (B)

Explanation: Coal mine workers and communities around coal mines face many adverse diseases, prominent among them pneumoconiosis (commonly known as black lung disease) due to the inhalation of coal dust, as well as diseases due to polluted drinking water. Hence option (b) is correct.

3. Consider the following statements regarding Trans fats.

1. All-natural fats and oils are a combination of monounsaturated, polyunsaturated and saturated fatty acids.
2. Trans fatty acids are formed during industrial partial hydrogenation of vegetable oil.
3. High intake of Trans fats reduces low density lipoproteins (LDL) and insulin levels.

Which of the above statements are correct?

(a) 1 and 2 only
(b) 1 and 3 only
(c) 2 and 3 only
(d) 1, 2 and 3

Answer: (A)

Explanation:

  • All-natural fats and oils are a combination of monounsaturated, polyunsaturated and saturated fatty acids. Trans fatty acids are formed during industrial partial hydrogenation of vegetable oil, a process widely commercialized to produce solid fats. Hence statement 1 and 2 are correct.
  • Trans fat increases low density lipoproteins (LDL), triglycerides and insulin levels and reduces beneficial high-density lipoproteins (HDL). Hence statement 3 is incorrect.

4. Acinetobacter baumannii, Enterococcus faecalis, Escherichia coli are associated with which if the following?

(a) Drugs administered to livestock as painkillers/anti-inflammatory drugs.
(b) Vectors that cause Dengue and Malaria
(c) Pathogens that have the ability to develop resistance to antibiotics.
(d) None of the above

Answer: (C)

Explanation: Some of the pathogens to look out for are Acinetobacter baumannii, Enterococcus faecalis, Escherichia coli, Salmonella typhi, Streptococcus pneumoniae and many more. These pathogens are commonly implicated as causative agents of healthcare associated infections because of their ability to develop resistance to antibiotics. Hence option (c) is correct.

5. Consider the following statements regarding Rice bran oil, which has gained popularity in recent times:

1. Rice bran oil is the oil extracted after the rice is dried and heated at high temperature.
2. It is rich in Oryzanol, which is proven to increase bad cholesterol and decrease good cholesterol.
3. It does not include any saturated fatty acids, monounsaturated fats and polyunsaturated fats.

How many statements given above are correct?

(a) Only one
(b) Only two
(c) All three
(d) None

Answer: (D)

Explanation:

  • It refers to the oil extracted from the extreme outer layer of rice called chaff. In recent times, it is being claimed as one of the healthiest cooking oils, because of its high smoke point of 232 °C (450 °F) and extreme mild flavour. These qualities make it apt for stir-frying and even deep-frying. Hence, statement 1 is incorrect.
  • It is rich in Oryzanol, which is proven to reduce bad cholesterol and increase good cholesterol. Hence, statement 2 is incorrect.
  • Rice bran oil has balanced fatty acid composition which includes saturated fatty acids, monounsaturated fats and polyunsaturated fats. This oil is rich in monounsaturated and polyunsaturated fats and is also free from trans-fats. Hence, statement 3 is incorrect.