Question Discussion & Solution

The correct answer is Solar cells.

Key Points

• A solar cell, or photovoltaic cell, is an electrical device that converts the energy of light directly into electricity by the photovoltaic effect.
• Photovoltaic cells consist of two or more layers of semiconductors with one layer containing positive charge and the other negative charge lined adjacent to each other.
• Sunlight, consisting of small packets of energy termed as photons, strikes the cell, where it is either reflected, transmitted or absorbed.
• When the photons are absorbed by the negative layer of the photovoltaic cell, the energy of the photon gets transferred to an electron in an atom of the cell.
• With the increase in energy, the electron escapes the outer shell of the atom.
• The freed electron naturally migrates to the positive layer creating a potential difference between the positive and the negative layer.
• When the two layers are connected to an external circuit, the electron flows through the circuit, creating a current.
• Advantages of Photovoltaic Cells:
  • ​Environmental Sustainability
  • Economically Viable
  • Accessible
  • Renewable
• Disadvantages of Photovoltaic Cells:
  • ​The efficiency of solar panels is low compared to other renewable sources of energy.
  • Power generated gets reduced during cloudy weather.
  • Long-range transmission of solar energy is inefficient and difficult to carry.
  • Photovoltaic panels are fragile and can be damaged relatively easily.

Concept:

Polymorphism is a feature of OOPs that allows the object to behave differently in different conditions. 

Explanation:

In C++ we have two types of polymorphism:
1. Compile-time Polymorphism – This is also known as static (or early) binding.
2. Runtime Polymorphism – This is also known as dynamic (or late) binding.

Compile-time Polymorphism
Function overloading and Operator overloading are examples of Compile time polymorphism.

If Government creates awareness among people about paying tax then the people will come to understand that paying tax to government is not a waste or burden. So, conclusion 1 follows. Increasing Tax won’t help to collect more money. So, conclusion 2 doesn’t follows.

In this Devotion is something different then living being. 

Hence, "Devotion" is the correct answer.

The correct answer is Copper.

Key Points

• Conductor of electricity
  • In physics and electrical engineering, a conductor is an object or type of material that allows the flow of charge in one or more directions.
  • Materials made of metal are common electrical conductors. 
  • Copper is considered to be a conductor because it conducts the electron current or flow of electrons fairly easily. Most metals are considered to be good conductors of electrical current. Copper is just one of the more popular materials that are used for conductors. Hence, Option 4 is correct.
  • If you have to define the meaning of electrical conductors in the simplest way, they are materials that allow electricity to flow through them easily.
  • If we compare two types of material and the first one allows better flow of electricity through it, then that material is said to be a good conductor of electricity.
  • An electrical conductor allows the electric charges to easily flow through them. The property of conductors to conduct electricity is called conductivity.
  • Such materials offer less opposition or resistance to the flow of charges.
  • Conducting materials allow easy charge transfer because of the free movement of electrons through them.

Additional Information

• • Some examples of conductors of electricity are
    • Copper
    • Aluminum
    • Silver
    • Gold
    • Graphite
    • Platinum
    • Water
    • People