Question Discussion & Solution

The correct answer is Lead and Tin.

Key Points

• Soldering is the process of joining two metal objects together by a third soft metal alloy which is called solder.
• Solder is a metal alloy that melts at a lower temperature than the metals being soldered.
• A commonly used alloy is solder, which is an alloy of tin (Sn) and lead (Pb).
• The alloy of tin-lead solder is a mixture of 63% tin and 37% lead. 63/37 solder melts at 183°C.
• So, Alloy of tin (Sn) and lead (Pb) is used for welding electrical wire together.

Additional Information

• Element Tin (Sn) belongs to Group 14 of the periodic table.
  • Atomic Number - 50
  • Atomic Mass  - 118.710 amu.
• Element Lead (Pb) belongs to Group 14.
  • Atomic Number - 82
  • Atomic Mass - 207.2 amu.

The correct answer is At the district level.

• At the district level is the "Special Juvenile Police Unit" constituted under the "Juvenile Justice (Care and Protection of Children) Act".

• Rajasthan Juvenile Justice (Care and Protection of Children) Rules, 2011
  • ​Special Juvenile Police Unit:
  • (1) The State Government shall appoint a Special Juvenile Police Unit at the District level within four months of the notification of these rules and the unit shall consist of a juvenile or child welfare officer of the rank of Police Inspector and two paid social workers having experience of working in the field of child welfare, of whom one shall be a woman.
    (2) The District Child Protection Unit or the State Government shall provide services of its two social workers to the Special Juvenile Police Unit for discharging their duties.
    (3) The Juvenile or Child Welfare Officer at the Police Station shall be a person with the aptitude and appropriate training and orientation to handle the cases of juveniles or children in terms of the provisions of the Act. 

• Juvenile Justice (Care and Protection of Children) Act, 2000
  • The State Government of Rajasthan has made the following rules under this act, called the Rajasthan Juvenile Justice (Care and Protection of Children) Rules, 2011.
  • The State Government, the Juvenile Justice Board, the Child Welfare Committee or other competent authorities or agencies, as the case may be, while implementing the provisions of these rules shall abide and be guided by the principles, specified in sub-rule (2).
  • The following principles shall, interalia, be fundamental to the application, interpretation and implementation of the Act.

Concept:

• Force: Force is a push or pull on an object. A force can cause an object to accelerate, slow down, remain in place, or change shape.

Force exerted = mass x acceleration

F = m × a

Acceleration = (Final velocity(v) - Initial velocity(u))/ time

\(a = \frac{{v - u}}{t}\)

Where F is the force exerted on the body, m is mass of the body, a is the acceleration of the body, v is final velocity, u is initial velocity and t s time.

Calculation:

Given,

Mass of body = 6 kg.

Change in velocity = (18 - 6) = 12 m/s

Time= 3 sec

Acceleration = 12/ 3 = 4m/s² 

Force = mass × acceleration

Force = 6 × 4 = 24 Newton.

Hence the correct option is 24 Newton

Concept-

• A cell is defined as the smallest unit of an organism with a nucleus.
• cells are made from the same major classes of organic molecules: nucleic acids, proteins, carbohydrates, and lipids.

• Example- a unit in the tissue of an animal muscle.

Key PointsParts of cell-

Cell membrane

• It is also called the plasma membrane,
• It is found in all cells and separates the interior of the cell from the outside environment.
• It is the outermost wall in the animal cell and placed next to the cell wall in the plant cell.
• Being an outer boundary of a cell, it provides shape to the cell.

Cell wall

• A cell wall is defined as the non-living component, covering the outmost layer of a cell.
• cell wall separates the interior contents of the cell from the exterior environment.
• It also provides shape, support, and protection to the cell and its organelles.

Nucleus

• A nucleus is defined as a double-membraned eukaryotic cell organelle that contains genetic material.
• It contains the cell’s hereditary information and controls the cell’s growth and reproduction
• It is responsible for coordinating many of the important cellular activities such as protein synthesis, cell division, growth, and a host of other important functions.

Ribosomes

• The ribosome is a complex molecule made of ribosomal RNA molecules and proteins that form a factory for protein synthesis in cells.

Additional Information  Cell was discovered by Robert Hooke in 1665, the cell has a rich and interesting history that has ultimately given way to many of today's scientific advancements.

Humans eat both vegies and meat so are omnivore, whereas Cats which eats meat only so its carnivore.