Electric Current (Physics) Part-II

The conversion of light (solar) energy into electrical energy is based on the phenomenon called photovoltaic effect. A photovoltaic cell is the basic unit of the system where the photovoltaic effect is utilized to produce electricity from light energy. Silicon is most widely used semiconductor material for constructing photovoltaic cell.

The conversion of light (solar) energy into electrical energy is based on the phenomenon called photovoltaic effect. A photovoltaic cell is the basic unit of the system where the photovoltaic effect is utilized to produce electricity from light energy. Silicon is most widely used semiconductor material for constructing photovoltaic cell.

The conversion of light (solar) energy into electrical energy is based on the phenomenon called photovoltaic effect. A photovoltaic cell is the basic unit of the system where the photovoltaic effect is utilized to produce electricity from light energy. Silicon is most widely used semiconductor material for constructing photovoltaic cell.

A photoelectric cell converts light energy into electric energy. The photoelectric effect, where electricity is generated from a material when it absorbs light, was first discovered in 1887 by Heinrich Hertz.

The photovoltaic effect is closely related to the photoelectric effect, with a critical difference. In the photoelectric effect, electrons are emitted into space. But, in the photovoltaic effect, electrons enter what we call the conduction band of the material.

The photoelectric device can capture high-energy photons and generate a high-voltage output, while the photovoltaic cell can capture low-energy photons and generate a high-current output. This combination can increase the power output and efficiency of solar PV systems.

The photoelectric effect is the emission of electrons when electromagnetic radiation, such as light, hits a material. And photoelectric device means which uses photoelectric effect, in other words which produces electricity/electric signal from light.

Photovoltaic cell is one such device. Photovoltaic cells or commonly known as solar cells have vast use in digital technology. For example, entire satellite communication depends on it, since this is the main source of power for it.

Photoemitting or light emitting diodes emit light on flow of electricity ie. reverse of photoelectric effect. Similarly, photodiode changes its electrical properties on receiving light.

It is like light controlled switch which allows flow of electricity on getting light but it does not generate electricity. Hence, option (b) is the correct answer.

'Net metering' is a billing mechanism that credits solar energy system owners for the electricity they add to the grid. For example, if a residential customer has a PV system on their roof, it may generate more electricity than the home uses during daylight hours.

If the home is net-metered, the electricity meter will run backwards to provide a credit against what electricity is consumed at night or other periods when the home's electricity use exceeds the system's output. Customers are only billed for their 'net' energy use.

As per IC Insights' Global Wafer Capacity 2021-2025 report, Taiwan led the world with 21.4% of global silicon wafer capacity installed in that country.

In second place was South Korea, which accounted for 20.4% of global silicon wafer capacity. Japan and China were at the third and fourth place respectively, India is not among the leading manufacturers of silicon wafers in the world.

The solar power tariffs in India are determined by the Central Electricity Regulatory Commission (CERC) and State Electricity Regulatory Commissions (SERCs) on the basis of competitive bidding.

Solar Energy Corporation of India (SECTI) has a Power trading license, but it does not determine solar power tariffs.

As on 31 March, 2024, the total wind power installed capacity of India is about 45.89 GW. Hence, statement of option (b) is not true.

On the basis of wind power installed capacity, India ranks fourth in the world after China, USA and Germany. Among Indian States, maximum wind power potential (at 100 m above ground level) is in Gujarat.

Madhya Pradesh has seventh rank in the country in wind power installed capacity. As per the data of 2021, other three statements are correct. However, Gujarat has surpassed Tamil Nadu in total wind power installed capacity in 2023.

As on 31 March, 2024, total wind power installed capacity in India is 45886.51 MW in which Gujarat has around 25.5% share (11722.72 MW) while Tamil Nadu has around 23.1% share (10603.54 MW).