Q3
4 marksSection A

Answer question numbers 3(a) – 3(d) on the basis of your understanding of the following paragraph and the related studied concepts:

Solar power in India is a fast developing industry. The country's solar installed capacity reached 30.071 GW30.071 \text{ GW} as of 31 July, 2019. India has the lowest capital cost per MW to install solar power plants. Solar electricity generation recorded nearly 3.4%3.4\% of total utility electricity generation in January 2019. The following table shows Annual Solar Power Generation of the last six years.


Year | Solar Power Generation (TWh)

2013 – 14 | 3.35

2014 – 15 | 4.60

2015 – 16 | 7.45

2016 – 17 | 12.09

2017 – 18 | 25.87

2018 – 19 | 39.27


Our country is lucky to receive solar energy for the greater part of the year. It is estimated that during a year India receives the energy equivalent to more than 5000 trillion kWh5000 \text{ trillion kWh} from the Sun.


3(a) What are solar cells?

3(b) How much voltage can be developed and how much electricity can be produced by one typical solar cell when exposed to the Sun?

3(c) The future of power generation by solar energy is bright in India. Give reason.

3(d) List two advantages of solar cells.

Our Environment
Sources of Energy and Environmental Impact
Official Answer

3(a) A solar cell is a device that converts solar energy (radiant light energy from the Sun) directly into electrical energy.


3(b) A typical single solar cell develops a voltage of 0.5 V0.5\text{ V} to 1 V1\text{ V} and can produce about 0.7 W0.7\text{ W} of electricity when exposed to the Sun.


3(c) The future of solar power generation in India is highly promising because India is a tropical country that receives abundant sunlight for the greater part of the year. It is estimated that India receives an enormous energy equivalent of more than 5000 trillion kWh5000\text{ trillion kWh} annually from the Sun, making it a highly viable and sustainable alternative to fossil fuels.


3(d) Two major advantages of solar cells are:

  1. Low Maintenance and No Moving Parts: They have no moving parts, require very little maintenance, and function satisfactorily without any focusing device.
  2. Suitability for Remote Areas: They can be set up in remote, inaccessible, or sparsely populated areas where laying conventional power transmission lines is highly expensive or commercially unviable.
solar cellconverts solar energyelectricity0.5 V to 1 V0.7 Wtropical country5000 trillion kWhno moving partsremote areas

Marking Scheme

  • 13(a): Correct definition of solar cell as a device converting solar energy to electricity. (1 mark)
  • 23(b): Correct voltage range (0.5 V0.5\text{ V} to 1 V1\text{ V}) and power output (~0.7 W0.7\text{ W}). (1 mark)
  • 33(c): Explaining India's tropical location and high annual solar insolation (>5000 trillion kWh> 5000\text{ trillion kWh}). (1 mark)
  • 43(d): Listing any two valid advantages (e.g., no moving parts, useful for remote areas). (1 mark)

Hint

Recall the parameters of a single solar cell from your study of energy sources, and use the geographical data provided in the passage to justify India's solar potential.

Quick Oral Answer

A solar cell converts solar energy directly into electricity. A single cell produces about 0.5 to 1 V0.5\text{ to }1\text{ V} and 0.7 W0.7\text{ W} of power.

Analysis & Explanation

This case-based question tests the understanding of solar energy as an eco-friendly alternative energy source.

  • Part (a) defines the fundamental function of a solar cell, which is direct conversion of solar radiation to electricity.
  • Part (b) provides the specific quantitative values of voltage (0.5 V0.5\text{ V} to 1 V1\text{ V}) and power (0.7 W0.7\text{ W}) associated with a single standard silicon solar cell.
  • Part (c) connects geographical advantages (tropical location, high annual solar insolation of >5000 trillion kWh> 5000\text{ trillion kWh}) to India's bright solar future.
  • Part (d) highlights the operational advantages (no moving parts, low maintenance) and socio-economic benefits (electrification of remote areas) of solar technology.

Common Mistakes

  1. 1Writing incorrect values for voltage and wattage (e.g., confusing 0.7 W0.7\text{ W} with 7 W7\text{ W} or 0.7 kW0.7\text{ kW}).
  2. 2Failing to link the geographical advantage of India (tropical location) in part (c).

Interesting Facts

Silicon, which is used for making solar cells, is abundant in nature, but the special grade silicon required for manufacturing solar cells is limited, making the process expensive.

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Frequently Asked Questions

How many marks does this question carry in CBSE Class 10 Science 2020?

This question carries 4 marks in the CBSE Class 10 Science 2020 examination.

Which chapter does this question come from in Science?

This question is from the chapter "Our Environment" in the CBSE Class 10 Science syllabus.

What topic does this question cover in Science?

This question covers the topic "Sources of Energy and Environmental Impact" from CBSE Class 10 Science.

What type of question is this in the CBSE Class 10 Science 2020 paper?

This question appears in Section A in the CBSE Class 10 Science 2020 paper.