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The correct answer is Rainwater infiltration.

Key Points

• Rainwater infiltration is the primary source of groundwater recharge, where rainwater percolates through soil and rocks, reaching underground aquifers.
• Groundwater recharge occurs when precipitation exceeds surface runoff and evaporation, allowing water to seep through permeable layers of soil and bedrock.
• The amount of groundwater recharge depends on factors like soil type, vegetation cover, land slope, and intensity of rainfall.
• Rainwater harvesting systems can enhance groundwater recharge by directing rainwater into recharge wells or pits.
• Proper management of rainwater infiltration is critical to sustaining groundwater levels, especially in areas prone to water scarcity.

Additional Information

• Snowmelt
• Snowmelt contributes to surface water sources such as rivers and streams, which can indirectly recharge groundwater in some areas.
• It plays a significant role in water supply systems in regions with high snowfall, such as the Himalayas or the Alps.
• However, its contribution to groundwater recharge is limited compared to direct rainwater infiltration.
• Ocean currents
• Ocean currents are large-scale movements of seawater driven by factors like wind, temperature, salinity differences, and Earth's rotation.
• They play a crucial role in regulating global climate and distributing heat but do not contribute to groundwater recharge.
• These currents are part of the hydrosphere and have no direct interaction with underground aquifers.
• River water
• River water can contribute to groundwater recharge in areas where rivers lose water to the surrounding aquifers (referred to as "losing streams").
• This process is more localized and depends on the geological conditions of the riverbed.
• However, river water recharge is secondary compared to rainwater infiltration, which is more widespread.

The correct answer is Sulphuric acid, hydrochloric acid, nitric acid.

Key Points

• Sulphuric acid (H₂SO₄), hydrochloric acid (HCl), and nitric acid (HNO₃) are mineral acids that are highly corrosive in their concentrated form.
• These acids are widely used in chemical industries for various purposes such as manufacturing fertilizers, dyes, explosives, and pharmaceuticals.
• Sulphuric acid is known as the "king of chemicals" due to its extensive industrial applications, including battery production and petroleum refining.
• Hydrochloric acid is a strong acid commonly used in cleaning processes, metal pickling, and the production of organic compounds.
• Nitric acid is used in the production of explosives, fertilizers (such as ammonium nitrate), and as a strong oxidizing agent in laboratories.

Additional Information

• Acetic acid, citric acid, tartaric acid (Option 1):
• These are organic acids primarily found in natural sources and are used in food and beverage industries.
• Acetic acid is a key component of vinegar and is used as a food preservative.
• Citric acid, found in citrus fruits, is used in food flavoring and as a preservative.
• Tartaric acid is commonly used in baking and as a stabilizer in food products.
• Unlike mineral acids, these organic acids are generally less corrosive and milder.
• Carbonic acid, phosphoric acid, boric acid (Option 2):
• These acids are weaker compared to the concentrated forms of mineral acids.
• Carbonic acid is formed when carbon dioxide dissolves in water and is responsible for the fizz in carbonated drinks.
• Phosphoric acid is used in the food industry (e.g., cola beverages) and in fertilizers.
• Boric acid is used as an antiseptic and in the manufacture of glass and ceramics.
• Formic acid, lactic acid, malic acid (Option 4):
• These are organic acids and are primarily found in biological systems.
• Formic acid is found in ant venom and is used in leather processing.
• Lactic acid is produced in muscles during anaerobic respiration and is used in food fermentation processes.
• Malic acid is found in apples and is used as a flavor enhancer in food products.

Given:

From the bar graph (values in crore Rs.)

Income: 2011 = 650, 2012 = 450, 2013 = 800

Expenditure: 2013 = 700, 2014 = 800, 2015 = 750

Formula used:

Percentage less = (Difference / Reference value) × 100

Calculation:

Total income from 2011 to 2013

⇒ 650 + 450 + 800 = 1900

Total expenditure from 2013 to 2015

⇒ 700 + 800 + 750 = 2250

Difference = 2250 − 1900 = 350

Percentage by which income is less = (350 / 2250) × 100 = \(15 \frac{5}{9}\)%

∴ Total income from 2011 to 2013 is \(15 \frac{5}{9}\)% less than total expenditure from 2013 to 2015.

Given:

Income in 2016 = 500 crore

Expenditure in 2016 = 400 crore

Profit in 2016 = 500 − 400 = 100 crore

In 2017: Income increased by 20%

Profit increased by 25%

Formula used:

New value = Old value × (1 + percentage / 100)

Expenditure = Income − Profit

Calculation:

Income in 2017 = 500 × (1 + 20/100)

⇒ 500 × 1.2 = 600

Profit in 2017 = 100 × (1 + 25/100)

⇒ 100 × 1.25 = 125

Expenditure in 2017 = 600 − 125 = 475

∴ The expenditure of the company in 2017 is 475 crore rupees.

Given:

2013 → Income = 800, Expenditure = 700

2014 → Income = 700, Expenditure = 800

2015 → Income = 800, Expenditure = 750

Formula used:

Profit / Loss = Income − Expenditure

Calculation:

Profit in 2013 = 800 − 700 = 100

Loss in 2014 = 700 − 800 = −100

Profit in 2015 = 800 − 750 = 50

Overall profit from 2013 to 2015 = 100 − 100 + 50 = 50

∴ The overall profit earned by the company from 2013 to 2015 is 50 crore rupees.

Given:

Income in 2015 = 800 crore 

Expenditure in 2015 = 750 crore  

Income in 2016 = 500 crore 

Expenditure in 2016 = 400 crore 

Formula used:

Profit = Income − Expenditure

Percentage more = (Difference / Original profit) × 100

Calculation:

Profit in 2015 = 800 − 750 = 50

Profit in 2016 = 500 − 400 = 100

Difference in profit = 100 − 50 = 50

Percentage more = (50 / 50) × 100 = 100%

∴ The profit earned by the company in 2016 is 100% more than the profit earned in 2015.

Given:

Odd years among given years = 2011, 2013, 2015

From the bar graph (values in crore Rs.)

2011 → Income = 650, Expenditure = 450

2013 → Income = 800, Expenditure = 700

2015 → Income = 800, Expenditure = 750

Formula used:

Profit = Income − Expenditure

Average profit = (Sum of profits) ÷ Number of years

Calculation:

Profit in 2011 = 650 − 450 = 200

Profit in 2013 = 800 − 700 = 100

Profit in 2015 = 800 − 750 = 50

Total profit in odd years = 200 + 100 + 50 = 350

Average profit = 350 ÷ 3 = 116.66

∴ The average profit earned by the company in odd years is 116.66 crore rupees.

The correct answer is A rise in temperature.

Key Points

• The reaction between quicklime (calcium oxide, CaO) and water (H2O) is an exothermic reaction, meaning it releases a significant amount of heat.
• The chemical equation for the reaction is: CaO + H2O → Ca(OH)2 + Heat. Here, calcium hydroxide (slaked lime) is formed as the product.
• The release of heat during this reaction causes the temperature to rise significantly, which is a key characteristic of this process.
• This reaction is widely used in construction, particularly in preparing lime mortar, as the heat generation helps in setting and hardening.
• Because of the heat produced, the reaction is considered hazardous if not handled properly, as it can cause burns or other safety issues.

Additional Information

• Quicklime (CaO) is an important industrial chemical used in various applications such as construction, agriculture, and chemical processes.
• Its reaction with water to form slaked lime (Ca(OH)2) is a fundamental chemical process that demonstrates the principles of exothermic reactions.

The correct answer is Pushyagupta.

Key Points

• The Sudarshan Lake was originally constructed by Pushyagupta, a provincial governor (Vaishya) of the Mauryan Empire during the reign of Chandragupta Maurya.
• The lake is mentioned in the Girnar Rock Inscription, attributed to Rudradaman I, a ruler of the Western Kshatrapas.
• This irrigation lake played a vital role in supporting agriculture and water management in the region of Junagadh (modern-day Gujarat).
• Rudradaman I later repaired and expanded the lake in 150 CE after it was damaged due to natural calamities.
• The Sudarshan Lake highlights the Mauryan Empire’s advanced knowledge of engineering and water resource management systems.

Additional Information

• Bhadrabahu:
• Bhadrabahu was a Jain monk and spiritual leader during the Mauryan period.
• He is known for his association with Chandragupta Maurya and is believed to have influenced the emperor to embrace Jainism.
• Bhadrabahu is not connected with the construction of Sudarshan Lake or any engineering projects.
• Tushaspha:
• Tushaspha was a Greek or Persian officer in the Mauryan administration, serving as a provincial governor under Chandragupta Maurya.
• He is known for his administrative contributions but is not associated with the Sudarshan Lake.
• Chanakya:
• Chanakya, also known as Kautilya or Vishnugupta, was the chief advisor and mentor of Chandragupta Maurya.
• He is famous for his treatise, Arthashastra, which provides insights into economics, politics, and statecraft.
• While Chanakya played a pivotal role in establishing the Mauryan Empire, he is not related to the construction of Sudarshan Lake.

Given:

Perimeter of rectangle = 13 cm

Width = \(2 \frac{3}{4}\) cm = 11/4 cm

Formula used:

Perimeter of rectangle = 2 × (Length + Width)

Calculation:

⇒ 2 × (L + 11/4) = 13

⇒ L + 11/4 = 13/2

⇒ L = 13/2 − 11/4

⇒ L = (26 − 11)/4

⇒ L = 15/4

⇒ L = \(3 \frac{3}{4}\) cm

∴ The length of the rectangle is \(3 \frac{3}{4}\) cm.