Question Discussion & Solution

In the question figure, there are 2 square blocks. Half of both square blocks are shaded and the other half is blank. One of the square blocks has its left half shaded and another square block has its right half shaded. Thus, in the answer figure, the square block whose left half is shaded should have its right block shaded and the square block whose right half is shaded should have its left half shaded.

Therefore option 1, 2, and 4 gets eliminated.

Hence, the figure in option 3 is the correct answer.

Hence, there is one such digit.

CONCEPT:

• Electric Power: The rate at which electrical energy is dissipated into other forms of energy is called electrical power i.e.,

\(P = \frac{W}{t} = VI = {I^2}R = \frac{{{V^2}}}{R}\)

Where V = Potential difference, R = Resistance and I = current.

EXPLANATION:

• Mathematically power can be written as,

\(\Rightarrow P = \frac{W}{t} = VI \)

If, W = 1 J and t = 1 sec, then P = 1 watt

• Thus the power of an electric circuit is said to be one watt or 1 ampere - volt if one joule of energy is consumed in one second. Therefore option 1 is correct.

The correct answer is Jaisalmer and Bikaner.

Key Points
Tropical Thorn Forest:

• These forests are found in Jaisalmer, Bikaner and Barmer.
• It comprises 6.25% of the forest in Rajasthan. 
• Rainfall varies from 0 to 25 cm. It is scanty in nature.
• Xerophytic vegetation is found in this forest. 
• Khejri, Rohida, and Jaal are prominent trees present in the Forest.

Additional Information

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.