BPSC Practice Test- 1 - BPSC (Bihar) MCQ

The wax vapours undergo incomplete combustion because of insufficient air. This incomplete combustion of wax vapour produces carbon particles. These unburnt carbon particles get heated up and start glowing. These glowing carbon particles make the flame bright yellow and luminous.

Statement 1 is incorrect.

• The Cabinet Committee on Economic Affairs approved a new Central Sector Scheme “PM Vishwakarma” for a period of five years (FY 2023-24 to FY 2027-28). The scheme aims to strengthen and nurture the Guru-Shishya parampara or family-based practice of traditional skills by artisans and craftspeople working with their hands and tools. The scheme also aims at improving the quality, as well as the reach of products and services of artisans and craftspeople and to ensure that the Vishwakarmas are integrated with the domestic and global value chains.
• Under PM Vishwakarma scheme, the artisans and craftspeople will be provided recognition through PM Vishwakarma certificate and ID card, Credit Support upto Rs.1 lakh (First Tranche) and Rs.2 lakh (Second Tranche) with a concessional interest rate of 5%.  The Scheme will further provide Skill Upgradation, Toolkit Incentive, Incentive for Digital Transactions and Marketing Support.
• The scheme will provide support to artisans and craftspeople of rural and urban areas across India. Eighteen traditional trades will be covered in the first instance under PM Vishwakarma.

• Particles of lead oxide in automobile exhaust can cause brain damage in children.

• Particles of mercury cause a disease called Minamata; which can lead to brain damage, mental retardation, and paralysis.

• Sulphur dioxide causes respiratory problems or lung damage.

Urea contains 46% nitrogen.

IMPORTANT POINTS

• Urea, also known as carbamide.
• It is an organic compound with the chemical formula CO(NH₂)₂
• This amide has two –NH2 groups joined by a carbonyl (C=O) functional group.
• It is a colorless, odorless solid, highly soluble in water
• Dissolved in water, it is neither acidic nor alkaline.
• The liver forms it by combining two ammonia molecules (NH₃) with a carbon dioxide (CO₂) molecule in the urea cycle.
• Urea is widely used in fertilizers as a source of nitrogen (N) and is an important raw material for the chemical industry.

USES OF UREA

• Urea is highly soluble in water and is therefore also very suitable for use in fertilizer solutions and as animal feed.
• For the manufacture of plastics specifically, urea-formaldehyde resin(Plywood adhesive Fevicol)
• For the manufacture of various glues (urea formaldehyde or urea-melamine-formaldehyde). The latter is waterproof and is used for marine plywood

Important Facts

• Pb(NO₃)₂ is the molecular formula for lead nitrate.

• 2Pb(NO₃)₂ → 2PbO + 4NO₂ + O₂

• On heating, lead nitrate decomposes into lead oxide, nitrogen dioxide, and oxygen, as shown in the reaction. Decomposition of lead nitrate produces lead oxide, nitrogen dioxide, and oxygen.

• When one mole of 2 Pb(NO₃)₂ is heated gives 2 moles of NO₂

• Here to balancing the equation, it shows - 4 moles of NO₂

Diamagnetic Substances

• Diamagnetic substances are those which have a tendency to move from stronger to the weaker part of the external magnetic field.

• In other words, unlike the way a magnet attracts metals like iron, it would repel a diamagnetic substance.

• Example: Bismuth, Copper, Lead, Silicon, Nitrogen (at STP), Water, and Sodium Chloride.

• The phenomenon of perfect diamagnetism in superconductors is called the Meissner effect.

Option Explanation

Ferromagnetic Substances

• Ferromagnetic substances are those which get strongly magnetised when placed in an external magnetic field.

• They have a strong tendency to move from a region of the weak magnetic field to strong magnetic field, i.e., they get strongly attracted to a magnet.

• Example: Iron, Cobalt, Nickel, Gadolinium, etc

Paramagnetic Substances

• Paramagnetic substances are those which get weakly magnetized when placed in an external magnetic field. They have a tendency to move from a region of weak magnetic field to a strong magnetic field, i.e., they get weakly attracted to a magnet.

• Example: Aluminium, Sodium, Calcium, Oxygen (at STP), and Copper Chloride.

• All in series

  

• All in parallel

  

• Two parallel resistances are in series with one resistance

  

• Two resistances in the series are in parallel combination with the third resistance

  

Important Points

Series Combination

• If different resistances are joined with each other such that there is only one path for the flow of electric current then the combination is called Series Combination.
• In series combination current through each resistor is constant.
• In series combination Potential difference across each resistor is different depending upon the value of resistance.
• If one component is fused, then the other components of the circuit will not function.

Parallel Combination

• If there is more than one path for the flow of current in a circuit then the combination of resistances is called Parallel Combination.
• In parallel combination current through each resistor is different.
• The potential difference across each resistor is constant.

If the earth stops rotating the value of g will remain the same at the poles and increase at other places.

Important Points:

Acceleration due to gravity (g)

Object receiving an acceleration due to the force of gravity acting on it is called gravitational acceleration.

The SI unit for the ‘g’ is m/s²

Its standard value is 9.8 m/s² on the surface of the earth at sea level.

Acceleration due to gravity is defined as

g = GM/R²

Where,

G = Universal gravitational constant

M = Mass of the earth

R = Radius of earth

P=V²/R

Where, V = Potential difference

R = resistance

It is given that,

R is fixed and V becomes double

V ' = 2 V

Now, P' = (2V)²/R = 4 V²/R

P' = 4 (P)

So, the electric power becomes four times its previous value.

The common method for converting biomass into ethanol is called fermentation. During fermentation, microorganisms (e.g., bacteria and yeast) metabolize plant sugars and produce ethanol.

Options explanation

Chemical process is a method or means of somehow changing one or more chemicals or chemical compounds. Such a chemical process can occur by itself or be caused by an outside force and involves a chemical reaction of some sort.

Physical change - Changes in the size or form of matter are examples of physical change

Biological processes are those processes that are vital for an organism to live, and that shape its capacities for interacting with its environment.

Confusing points

Any hydrocarbon fuel that is produced from an organic matter (living or once-living material) in a short period of time (days, weeks, or even months) is considered a biofuel.

Biofuels may be solid, liquid, or gaseous in nature.

Solid: Wood, dried plant material, and manure

Liquid: Bioethanol and Biodiesel

Gaseous: Biogas

Important points

Classification of Biofuels:

1st generation biofuels are also called conventional biofuels. They are made from things like sugar, starch, or vegetable oil. Note that these are all food products. Any biofuel made from a feedstock that can also be consumed as human food is considered a first-generation biofuel.

2nd generation biofuels are produced from sustainable feedstock. The sustainability of a feedstock is defined by its availability, its impact on greenhouse gas emissions, its impact on land use, and by its potential to threaten the food supply. No second-generation biofuel is also a food crop, though certain food products can become second-generation fuels when they are no longer useful for consumption. Second-generation biofuels are often called “advanced biofuels.”

3rd generation biofuels are biofuels derived from algae. These biofuels are given their own separate class because of their unique production mechanism and their potential to mitigate most of the drawbacks of 1st and 2nd generation biofuels.

4th generation biofuels: In the production of these fuels, crops that are genetically engineered to take in high amounts of carbon are grown and harvested as biomass. The crops are then converted into fuel using second-generation techniques.

Options explanation

DNA ligase is a specific type of enzyme, a ligase, that facilitates the joining of DNA strands together by catalyzing the formation of a phosphodiester bond. It plays a role in repairing single-strand breaks in duplex DNA in living organisms, but some forms may specifically repair double-strand breaks.

Histone is a protein that provides structural support to a chromosome. In order for very long DNA molecules to fit into the cell nucleus, they wrap around complexes of histone proteins, giving the chromosome a more compact shape. Some variants of histones are associated with the regulation of gene expression

Confusing points

DNA Replication

This is a complex process that takes place during cell division, (interphase, S phase) whereby DNA makes copies (duplicates) before the cell divides through mitosis and meiosis.

DNA replication is a semiconservative process where a parental strand (template) is used to synthesize a new complementary daughter strand using several protein elements which include enzymes and RNA molecules.

DNA replication process uses DNA polymerase as the main enzyme for catalyzing the joining of deoxyribonucleoside 5′-triphosphates (dNTPs) forming a growing chain of DNA.

Other proteins are also involved for initiation of the process and copying of DNA, along with proofreading capabilities to ensure the replication process takes place accurately.

Therefore DNA replication is a process that produces identical helices of DNA from a single strand of the DNA molecule.

DNA replication is an essential mechanism in enhancing cell growth, repair, and reproduction of an organism.

Important points

DNA replication takes place in three major steps.

Opening of the double-stranded helical structure of DNA and separation of the strands

Priming of the template strands

Assembly of the newly formed DNA segments.

Options explanation

• William Harvey was an English physician who made influential contributions in anatomy and physiology.

• Marie Salomea Skłodowska Curie was a Polish and naturalized-French physicist and chemist who conducted pioneering research on radioactivity.

• Sir James Chadwick, CH, FRS was a British physicist who was awarded the 1935 Nobel Prize in Physics for his discovery of the neutron in 1932.

Confusing points

Function

ATP hydrolysis provides the energy needed for many essential processes in organisms and cells. These include intracellular signaling, DNA and RNA synthesis, Purinergic signaling, synaptic signaling, active transport, and muscle contraction. These topics are not an exhaustive list but include some of the vital roles ATP performs.

DNA/RNA Synthesis

DNA and RNA synthesis require ATP. ATP is one of four nucleotide-triphosphate monomers that is necessary during RNA synthesis. DNA synthesis uses a similar mechanism, except in DNA synthesis, the ATP first becomes transformed by removing an oxygen atom from the sugar to yield deoxyribonucleotide, ATP.

Important points-

The body is a complex organism, and as such, it takes energy to maintain proper functioning. Adenosine triphosphate (ATP) is the source of energy for use and storage at the cellular level. The structure of ATP is a nucleoside triphosphate, consisting of a nitrogenous base (adenine), a ribose sugar, and three serially bonded phosphate groups.

Options explanation

• William Harvey was an English physician who made influential contributions in anatomy and physiology.

• Severo Ochoa de Albornoz was a Spanish physician and biochemist, and joint winner of the 1959 Nobel Prize in Physiology or Medicine with Arthur Kornberg.

• Sir Godfrey Newbold Hounsfield was an English electrical engineer who shared the 1979 Nobel Prize for Physiology or Medicine with Allan MacLeod Cormack for his part in developing the diagnostic technique of X-ray computed tomography.

Confusing points

• Photosynthesis is critical for the existence of the vast majority of life on Earth. It is the way in which virtually all energy in the biosphere becomes available to living things.

• As primary producers, photosynthetic organisms form the base of Earth’s food webs and are consumed directly or indirectly by all higher life forms.

• Additionally, almost all the oxygen in the atmosphere is due to the process of photosynthesis. If photosynthesis ceased, there would soon be little food or other organic matter on Earth, most organisms would disappear, and Earth’s atmosphere would eventually become nearly devoid of gaseous oxygen.

Important points

photosynthesis, the process by which green plants and certain other organisms transform light energy into chemical energy. During photosynthesis in green plants, light energy is captured and used to convert water, carbon dioxide, and minerals into oxygen and energy-rich organic compounds.