Daily Static MCQs for UPSC & State PSC Exams - Science and Technology (13 October 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.

Which of the above statements is/are correct?

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

Answer: (C)

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. 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 2 is not correct.

2. Consider the following statements regarding Machine to Machine communications (M2M):

1. Machine to Machine communications refer to automated applications which involve machines or devices communicating through a network without human intervention.
2. It enables data to be transmitted from one device to another device through wired and wireless communications networks.

Which of the above statements is/are correct?

(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2

Answer: (C)

Explanation: M2M communications refer to automated applications which involve machines or devices communicating through a network without human intervention. Sensors and communication modules are embedded within M2M devices, enabling data to be transmitted from one device to another device through wired and wireless communications networks. Hence, both statements are correct.

3. Acinetobacter baumannii, Enterococcus faecalis, Escherichia coli are:

(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.

4. Consider the following statements regarding Vitamin D deficiency:

1. Vitamin D deficiency is often associated with rickets.
2. In rickets, the bone tissue does not correctly mineralise calcium and phosphorus, leading to softening of bones resulting in skeletal deformities.
3. Vitamin D plays a crucial role in depression, mood swings, anxiety and sleep quality.

How many of the above statements is/are correct?

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

Answer: (C)

Explanation: Vitamin D deficiency is often associated with rickets. In rickets, the bone tissue does not correctly mineralise calcium and phosphorus, leading to softening of bones resulting in skeletal deformities. It plays a crucial role in depression, mood swings, anxiety and sleep quality. Hence, all statements are correct.

5. Consider the following statements:

1. Dengue is a viral infection transmitted to humans through the bite of infected female mosquitoes.
2. When a mosquito bites, it not only sucks blood but also secretes saliva that enters blood stream.
3. Specific medications and vaccine are available to treat dengue.

How many of the above statements is/are correct?

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

Answer: (B)

Explanation: Dengue is a viral infection transmitted to humans through the bite of infected mosquitoes. The primary vectors that transmit the disease are female Aedes aegypti mosquitoes and, to a lesser extent, Ae. albopictus. There is no specific treatment for dengue/severe dengue. Early detection of disease progression associated with severe dengue, and access to proper medical care lowers fatality rates of severe dengue to below 1%. When a mosquito bites, it not only sucks blood but secretes saliva. This saliva enters the blood. There is an exchange of fluids between the mosquito and the bloodstream. Hence, statement 3 is incorrect.