Question Discussion & Solution

The correct answer is 2 ms^-2

• We know that according to Newton's 2^nd law, 
  • ​Force = Mass × Acceleration
  • or \((\vec F = m \times \vec a)\)
• Here, F = 100 N and Mass = 50 Kg
• So, 100 = 50x a ⇒ a = 100/50 = 2.
• Hence, the acceleration will be 2 ms^-2.

• Force: A force is something that changes the state of rest or motion of a body.
  • It causes the body to start moving if it is at rest or stops if it is in motion or deflects from the initial path.
  • Force is a vector quantity having SI unit Newton (N) and dimension (MLT^-2).
• According to Newton’s Second law of motion
  • The rate of change of momentum of a body is directly proportional to the resulting force acting on a body
  • Mathematically it can be expressed as 
• \(\vec F \propto \frac{{d\vec p}}{{dt}}\;or\;\vec F = m \times a\)

The correct answer is Windows, Icons, Menus.

• In a GUI-based operating system, the graphical user interface is based on Windows, Icons, Menus.

Key Points

• A  graphical user interface(GUI) uses windows, icons, and menus to perform various commands, such as opening, deleting, and moving files.
• A GUI operating system is primarily navigated using a mouse, a keyboard can also be used via keyboard shortcuts or arrow keys. 

The correct answer is in 1957.

• Rajasthan State Sports Council was established in 1957.

Key Points

• Rajasthan State Sports Council is the premier body in Rajasthan at the State level which looks after the development of sports activities and providing coaching to the state players.
• It was set up in the year 1957.
• Its headquarters is in Jaipur, Rajasthan.
• Ashok Chandna is the current sports minister of Rajasthan.

The correct answer is to Correct the eye defects.

• Lenses are widely used in spectacle to correct eye defects.
• There are three common defects of vision that can be corrected with the help of suitable spherical lenses (convex lenses or concave lenses).
• Myopia is also known as Short-sightedness or nearsightedness.
  • Due to this defect, the person cannot see the distant objects clearly but he/she can see the nearby objects clearly.
  • The far point of the eye having myopia is less than infinity.
  • The defect is caused due to the high converging power of eye-lens or due to the eyeball being too long.
  • It can be corrected by making use of spectacles containing concave lenses.
• Hypermetropia is also known as Long-sightedness or farsightedness.
  • Due to this defect, the person cannot see the nearby objects clearly but he/she can see the distant objects clearly.
  • The near point of a hypermetropic eye is more than 25 centimetres away.
  • The defect is caused due to the low converging power of eye-lens or due to the eye-ball being too short.
  • It can be corrected by making use of spectacles containing convex lenses.
• Presbyopia is a vision disease caused mostly in old age.
  • The ciliary muscles become weak and the eye-lens become rigid and the eye loses its power of accommodation in old age in this vision defect.
  • In Presbyopia the person cannot see the nearby objects clearly due to loss of power of accommodation of the eye.
  • The near point of the old person having presbyopia gradually reduces and becomes much more than 25 centimetres away.
  • It can be corrected by making use of spectacles containing convex lenses.
• A person suffering from both Myopia and Hypermetropia uses spectacles having bifocal lenses in which the upper part consists of a concave lens to correct myopia and the lower part consists of a convex lens to correct hypermetropia.

The correct answer is Sodium and potassium.

Key Points

• Sodium and Potassium metals are the two metals which are soft and can be cut with a knife.
  • Both belong to Alkali metals [first group of periodic table]
  • They are reactive metals.
  • As the atomic size increases down the group, so the force of attraction between the valence electron and nucleus decreases. 
  • Metallic bonds are not strong.
  • Potassium is softer than sodium.

Additional Information 

• Mercury- In a liquid state at room temperature, It is unique as a metal.
  • Mercury (Hg), also known as quicksilver.
  • Atomic Number- 80
• Zinc- Related to low Melting group.
  • Atomic Number- 30
  • Symbol- Zn
• Tin- It is a soft silvery-white metal with a bluish tinge.
  • Atomic Number- 50
  • Symbol- Sn