Bissoy.com
Doctors Medicines MCQs Q&A

Solar cell works in:

Solar cell works in: Correct Answer No external bias is required

CONCEPT:

Solar Cell:

  • A solar cell is basically a p-n junction that generates emf when solar radiation falls on the p-n junction.
  • It works on the same principle (photovoltaic effect) as the photodiode, except that no external bias is applied and the junction area is kept much larger for solar radiation to be incident because we are interested in more power.
  • A p-Si wafer of about 300 μm is taken over which a thin layer (~0.3 μm) of n-Si is grown on one side by the diffusion process.
  • The other side of p-Si is coated with a metal (back contact). On the top of the n-Si layer, a metal finger electrode (or metallic grid) is deposited. This acts as a front contact.
  • The metallic grid occupies only a very small fraction of the cell area (< 15%) so that light can be incident on the cell from the top.
  • The generation of emf by a solar cell, when light falls on, it is due to the following three basic processes: generation, separation, and collection:
    1. Generation of e-h pairs due to light (with hν > Eg) close to the junction.
    2. Separation of electrons and holes due to electric field of the depletion region. Electrons are swept to n-side and holes to p-side.
    3. The electrons reaching the n-side are collected by the front contact and holes reaching the p-side are collected by the back contact.
  • Thus p-side becomes positive and the n-side becomes negative giving rise to photovoltage.
  • When an external load is connected a photocurrent flows through the load.

[ alt="slr" src="//storage.googleapis.com/tb-img/production/21/07/slr.PNG" style="height: 174px; width: 250px;">

EXPLANATION:

We know that solar cell works on the same principle (photovoltaic effect) as the photodiode, except that no external bias is applied and the junction area is kept much larger for solar radiation to be incident because we are interested in more power.

Hence, option 3 is correct.

Related Questions

The following sentences form a paragraph. The FIRST and SIXTH sentences of the paragraph are given. The rest of the sentences are numbered as B, C, D, ad E, which are not in proper order. Read the sentences and place them in chronological order. National Solar Mission is one of the eight missions set up of National Action Plan on Climate change (NAPCC) that was released on 30 June 2008. With this ambitious target, India will become one of the largest Green Energy producers in the world, surpassing several developed countries. Government stepped up India’s solar power capacity target under the Jawaharlal Nehru National Solar Mission (JNNSM), by five times, reaching 1,00,000 MW by 2022. The target will principally comprise 40 GW Rooftop and 60 GW through Large and Medium Scale Grid Connected Solar Power Projects. The new targets were approved in June 2015. During recent times with improvement in technology and scaling up production capacities, solar energy has become cost-competitive and targets seem to be more viable now.
In a solar operated steam power plant, water is converted into steam via solar heat. If the effective area of solar plate is 200m2, value of solar constant is 1.362KW per m2, efficiency of solar components is 17% and overall thermal efficiency of steam cycle desired is 12%. Find the turbine power output?
Column A lists the cell parts and Column B lists the functions of the cell part. Column A Column B i. Cell wall A. Control what happens ii. Cell membrane B. Supports the cell. iii. Cytoplasm C. Controls what passes in and out of the cell. iv. Nucleus D. Cell reactions happen in it. Which one of the following options is correct?
A, B, C, D, K, L, M and O are researchers and are working in three different institutes, X, Y and Z. They are working in three different areas namely, solar energy, sustainable development, and rainwater harvesting for agricultural purpose. Not less than two or more than three researchers are working in the same area and not more than three of them are working the same institute. K is researching in the sustainable development in the institute Y with B who is doing research in rainwater harvesting. A and M are doing research in the same area but not in sustainable development and are not working in the institute Y. C is researching in solar energy in the institute Z, only with D who is working in sustainable development. L is researching in rainwater harvesting area and not working in the institute where A works. O is not doing research in the solar energy. Choose option for answering question, In which of the institute/institutes at least one researcher is working in the area of solar energy ?
Q.(1-4): Answer the questions on the basis of the information given below. * F,G and H are insurance companies , Q,R,S and T are private detectives .Each detective works for at least one of the insurance companies. * Q always works for F and at least one of the other companies. Some of the time G employs only one of these detectives,' the rest of the time it employs exactly two of them. *F and H each employ exactly two of these detectives all the time. If R works for H only, and if S works for G and H only, T works for--
Statements followed by some conclusions are given below. Statements:  A. Ravi works more than Meera, who works 8 hours per day. B. Yuvi works 9 hours per day, which is 1 hour less than Ravi. Conclusions: I. Ravi works 8 hours. II. Yuvi and Ravi per day both works more than Meera. Find which of the given conclusions logically follow from the given statements.  A. Only conclusion I follows. B. Only conclusion II follows. C. Both I and II follow. D. Neither I nor II follows.
What are the limitations of solar energy? 1. Collecting solar energy over large areas and converting it to other forms that can be conveniently transported, stored and used in existing equipment is not economical 2. Low density of solar energy as compared to coal, oil and gas 3. Its major applications are photothermal conversion, solar water heating, green housing technology and photo voltaic conversion Select the correct answer using the codes given below:
With reference to technologies for solar power production, consider the following statements: 1. 'Photovoltaics' is a technology that generates electricity by direct conversion of light into electricity, while 'Solar Thermal' is a technology that utilizes the Sun's rays to generate heat which is further used in the electricity generation process. 2. Photovoltaics generates Alternating Current (AC), while Solar Thermal generates Direct Current (DC). 3. India has a manufacturing base for Solar Thermal technology, but not for Photovoltaics. Which of the statements given above is/are correct?
How many Solar Parks and Ultra Mega Solar Power Projects were proposed to be setup under the scheme for development of Solar Parks and Ultra Mega Solar Power Projects?
If Arif works alone he will take 20 more hours to complete a task than if he works with Babu to complete the task. If Babu work alone, he will take 5 more hours to complete the task than if he works with Arif to complete the task. What is the ratio of the time taken by Arif to than taken by Babu if each of them works alone to complete the task?