Question Discussion & Solution

The correct answer is Natural Gas.

Key Points

•  Fossil Fuel: Fossil Fuels are the fuels generated from the residues of living organisms (which remained buried under the earth for millions of years).
  • Examples: Coal, Petroleum, and Natural gas.
  • They are also known as Non-Renewable Natural Resources.​

 Additional Information

• Natural Gas: It is considered the best fuel because of the inflammable nature of its constituents(83% methane and 16%ethane).
  • It is used in the production of artificial chemical fertilizers. 
• Coke: It is obtained by the strong heating of coal in the absence of air as a residual substance. 
  • It contains 80-85% carbon.
  • Coke is used in the extension of metals as a reducing agent.
• Producer Gas: It is a mixture of nitrogen and carbon monoxide(in 2:1 ratio).
  • It is used in the manufacture of glass and for metallurgy. 

The correct answer is Its momentum is doubled.

Key Points

• Momentum is a vector quantity; it has both magnitude and direction.
• Isaac Newton’s second law of motion states that the time rate of change of momentum is equal to the force acting on the particle.
• Momentum can be calculated by multiplying the mass of an object by its forward velocity. (mv = kg*m/s).
• Mass and velocity are both directly proportional to the Momentum.
  • If you increase either mass or velocity, the Momentum of the object increases proportionally.
  • If you double the mass or velocity, you double the Momentum.
  • If you halve the mass or velocity, you half the Momentum.
• Newton's laws of motion-
  • ​Newton’s first law states that if a body is at rest or moving at a constant speed in a straight line, it will remain at rest or keep moving in a straight line at constant speed unless it is acted upon by force. This postulate is known as the law of inertia.
  • Newton’s second law is a quantitative description of the changes that a force can produce in a body's motion. It states that the time rate of change of a body's momentum is equal in both magnitude and direction to the force imposed on it. The momentum of a body is equal to the product of its mass and its velocity.
  • Newton’s third law states that when two bodies interact, they apply forces to one another equal in magnitude and opposite in direction. The third law is also known as the law of action and reaction. This law is important in analyzing static equilibrium problems, where all forces are balanced, but it also applies to bodies in uniform or accelerated motion.

Important Points

• Acceleration, the rate at which velocity changes with time in terms of both speed and direction. A point or an object moving in a straight line is accelerated if it speeds up or slows down. Motion on a circle is accelerated even if the speed is constant because the direction is continually changing.
• Kinetic energy, a form of energy that an object or a particle has because of its motion. If work, which transfers energy, is done on an object by applying a net force, the object speeds up and gains kinetic energy. Kinetic energy is a property of a moving object or particle and depends not only on its motion but also on its mass.
• Potential energy, stored energy that depends upon the relative position of various parts of a system. Spring has more potential energy when it is compressed than stretched. A steel ball has more potential energy raised above the ground than it has after falling to Earth.

Logic: second Number = First Number × 2 + 1

Third Number = First Number ÷ 2 + 1

(56, 113, 29) → 56 × 2 + 1 = 113, 56 ÷ 2 + 1 → 29

(68, 137, 33) → 68 × 2 + 1 = 137, 68 ÷ 2 + 1 → 35 ≠ 33

( 72, 145, 37) → 72 × 2 + 1 = 145, 72 ÷ 2 + 1 → 37

(84, 169, 43) → 84 × 2 + 1 = 169, 84 ÷ 2 + 1 → 43

The correct answer is option 2 i.e C₄H_10.

Concept:

Hydrocarbons

• Compounds made of carbon and hydrogen atoms only are called hydrocarbons.
• Saturated hydrocarbons:
  • The hydrocarbons in which carbon atoms are singly bonded are called saturated hydrocarbons.
  • Saturated hydrocarbons are also called alkanes or paraffin.
    • The general formula of alkane– CnH2n+2.
• Unsaturated hydrocarbons:
  • The hydrocarbons in which carbon atoms are either doubly or triply bonded are called unsaturated hydrocarbons.
  • Doubly bonded (carbon atoms) hydrocarbons are called alkenes.
  • The general formula of alkene is CnH2n.

• The formula for alkane should be mentioned C_nH_2n+2

Explanation:

The correct answer is Uttarakhand

Key Points

• Nanda Devi is India's second-highest mountain peak, after Kanchenjunga.
  • But it is the highest mountain peak entirely located in India.
  • Height: 7,817 metres
  • Location: Uttarakhand.

Additional Information

About Uttarakhand (as of August 2021):

• Uttarakhand, formerly Uttaranchal, state of India, located in the northwestern part of the country.
  • Uttarakhand was carved out from Uttarpradesh on 9 November 2000 as the 27th State of India.
  • It is bordered to the northwest by Himachal Pradesh, to the northeast by the Tibet Autonomous Region of China, to the southeast by Nepal, and to the south and southwest by the Indian state of Uttar Pradesh.
  • Its capital is the northwestern city of Dehra Dun.
  • Governor: Baby Rani Maurya
  • CM: Pushkar Singh Dhami
  • State flower: Saussurea obvallata
  • State Bird: Alpine musk deer
  • National park: Valley of Flowers National Park (UNESCO sites), Rajaji National Park, Nanda Devi National Park, Gangotri National Park, Jim Corbett (1st National park in India).