Question Discussion & Solution

Joule is the SI unit of Energy.

Similarly,

Pascal is the SI unit of pressure.

Hence, pressure is the correct answer.

Additional Information 

* S.I Unit of Resistance is the Ohm.

* S.I Unit of Energy is Joule.

* S.I Unit of Volume is the Cubic meter.

* S.I Unit of Force is Newton.

* S.I Unit of Area is the Square meter.

* S.I Unit of Temperature is Kelvin.
Important Points 

There is a total of 9 S.I units.

1. 7 of them are fundamental units.

2. 2 of them are Supplementary units.

The correct answer is Sunderban Delta.

• Sunderban Delta is the largest delta in India.

Key Points

• Sunderbans has spread over 1330.10 sq. km.
• It is formed by the Ganga and Brahmaputra rivers in West Bengal and Bangladesh. 
• Sundarbans is also known for the mangrove forest which is one of the largest such forests in the world.
• Sundarbans was included in the World Heritage site in 1987.
• East Flowing Rivers are known as Delta forming rivers
  • East flowing rivers do not form estuaries.
  • East flowing rivers fall in the Bay of Bengal.

Additional Information

• A delta is a depositional feature of a river which is formed at the mouth of the river. 
• Largest River without is Delta Narmada and Tapti.

Total number of boxes of matchsticks = 3600

Total number of cartons = 10

Let the number of packets in one carton be x.

⇒ Number of packets in 10 cartons = 10x.

Number of boxes of matchstick in a packet = 30

⇒ Number of boxes of matchstick in 10x packets = 30(10x) = 300x

So, we have:

Total number of boxes = Number of boxes of matchstick in 10x packets

⇒ 300x = 3600

⇒ x = 12

The correct answer is Selenium.

Key Points

•  A trace element/minor element; is a chemical element whose concentration is very low.
• These include iron, manganese, copper, iodine, zinc, cobalt, fluoride and selenium.
• These minerals are present in living tissues of human body in small amounts.
• Some of them are known to be nutritionally essential, others may be essential and the remainder are considered to be nonessential.

Concept:

• The laws dealing with ideal gases naturally called ideal gas laws, and the laws determined in the seventeenth century by Boyle's observational work and in the eighteenth century by Charles.
• The Boyles Law states that the gas pressure is inversely proportional to the gas volume for a given mass of gas stored at a constant temperature.
• Charles Law states that the gas volume is directly proportional to the gas temperature for a given fixed mass of gas stored at a constant pressure. 
• An ideal gas is a gas that follows the equation:

PV = nRT at all temperatures and pressure, where P = Pressure of the ideal gas. V = Volume of the ideal gas n = Amount of ideal gas measured in terms of moles 

R = Universal gas constant T = Temperature

Mole Concept -

•  The quantity one mole of a substance signifies 6.022 × 1023 number of particles of that substance which may be atoms, molecules, or ions.
• The quantity is a universal constant like Dozen, Gross, etc., and is known as Avogadro number, denoted by NA. after the scientist Amedeo Avogadro.
• Examples- In one mole of H2, there are 6.022 × 1023 molecules of hydrogen, and the number of atoms is 2 × 6.022 × 1023, as one molecule of hydrogen contains two-atom each.
• The mass of one mole of a substance is called its Molar Mass (M) or Atomic mass expressed in grams.
• The volume occupied by a mole of gas is 22.4 L at NTP, called its Molar Volume.
• The no. of moles (n) is calculated as =

The number of particles / Avogadro’s number.

To summarise, we can say, 

Calculation:

• The molar mass of 1 mole of H₂SO₄ is =

2 × 1 + 32 + 4 × 16 = 98g

• The molar mass of 1 mole of Silver, Ag is its molecular mass 108g.
• The molar mass of CO₂ is = 12 + 2× 16 = 44g.
• 44g of CO₂ means one mole.
• 1 mole of Oxygen weighs 16 + 16 = 32g.
• Hence, the highest mass is of 1 mole of Ag.