Question Discussion & Solution

The pattern followed here is:

This is an alternate series of subtraction. The first number is subtracted by 2 to get the second number and then 4 is subtracted from the second number to get the third number and so on.

Hence, 42 is the correct answer.

CONCEPT:

• Plane mirror: This mirror is straight without any inward or outward curve.
  • It forms a virtual image and upright image which is of size as same as the object.
  • The bathroom mirrors are an example.
• Concave mirror: The mirrors curved inside on the reflecting side are called concave mirrors.
  • These mirrors produce a real, inverted, and magnified image of the object.
  • These are used in reflecting telescopes, shaving mirrors, and ophthalmoscope.

• Convex mirror: It is an outward curved mirror that produces a diminished image.
  • Convex mirrors either diverge a parallel beam of light into all directions or gather light from all directions and produce a parallel beam out of it.

EXPLANATION:

• Following are the reasons as to why a convex mirror is used as a rearview mirror in the vehicle

• The image formed by the convex mirror is virtual and erect in contrast to that of the real but inverted image of the concave mirror.
• It gathers light from all directions and aligns it as a parallel beam so that it provides a wider view to the viewer. That's why the convex mirror is used as a rear-view mirror in vehicles. So option 2 is correct.

The correct answer is Stapes.

• Stapes is the smallest bone in the human body.

Key Points

• The smallest bone in the human body is called stapes, located in the middle ear.
• The size of the staples is 3mm × 2.5 mm. 
• There are three bones in the middle ear, ​Malleus, Stapes, and Incus.
• ​The Stapes is the smallest of the three bones and it looks like a bell.​
• It is the innermost bone of our auditory ossicles in the middle ear, which are responsible for transmitting sound waves from the air outside to the fluid-filled labyrinth (cochlea).

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Additional Information

• The malleus or hammer is a hammer-shaped small bone or ossicle of the middle ear which connects with the incus and is attached to the inner surface of the eardrum.
  • The word is Latin for hammer or mallet.
  • It transmits the sound vibrations from the eardrum to the incus.
• The incus, also known as the “anvil,” is the middle of three small bones in the middle ear.
  • The incus transmits vibrations from the malleus to the stapes.
• In anatomy, the scapula (plural scapulae or scapulas), also known as the shoulder bone, shoulder blade, wing bone, or blade bone,
  • It is the bone that connects the humerus (upper arm bone) with the clavicle (collar bone).
• The rib cage is the arrangement of ribs attached to the vertebral column and sternum in the thorax of most vertebrates that encloses and protects vital organs such as the heart, lungs, and great vessels.
• The hip bone (os coxae, innominate bone, pelvic bone, or coxal bone) is a large irregular bone, constricted in the center and expanded above and below. In some vertebrates (including humans before puberty).
• it is composed of three parts: the ilium, ischium, and the pubis.

The correct answer is Three.

According to the Dowry Prohibition Act, 1961, 3 conditions related to dowry have been stated.

Key Points

Dowry Prohibition Act, 1961

• Dowry Prohibition Act, Indian law, enacted on May 1, 1961, intended to prevent the giving or receiving of a dowry.
• Under the Dowry Prohibition Act, dowry includes property, goods, or money given by either party to the marriage, by the parents of either party or by anyone else in connection with the marriage.
• There are three occasions related to dowry.
  • One is before the marriage,
  • The second is at the time of marriage 
  • The third is at any time after the marriage. The third occasion may appear to be an unending period. But the crucial words are in connection with the marriage of the said parties.

The correct answer is the stem.

Key Points

• Jute fibers are the bast fibers, generally soft and shiny.
• Jute is a natural fibre.
• Jute fiber consists of plant material cellulose and lignin.
• The jute fibrous are separated from the stem by using the following process: 
• The process includes three steps:
  • Retting
  • Stripping
  • Picking 
• Retting means soaked in water. In this process, the stem of jute plants is taken and made into bundles.
• These bundles are immersed in slow-running water, so the bundle gets wetted.
• Stripping process - In this process the non-fibrous thing is separated from the bundles. This process is done by hand.
• Picking process - After stripping the workers picked the fibrous from the mass of the stem. So, jute fiber is obtained from the stem of the jute plant. Hence, Option 4 is correct.
• The wetting process is of two types:
  • Ribbon wetting
  • Stem wetting After wetting the stripping process is done.

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• Bast fibers are the fibers extracted from the past which surround the stem.
• Bast is also known as phloem.
• Jute is also called golden fiber due to its golden color and high economical value.
• It is a biodegradable and recyclable fiber. Jute fibers are used to make mats, twins and ropes, gunny sacks, and bags. Jute fiber has high tensile strength, smooth luster, and is silky and shiny.
• The main source of jute fibre is Corchorus olitorius.