Question Discussion & Solution

Concept:

• Food chain:​ The sequence of living organisms in a community in which one organism consumes another organism to transfer food energy is called a food chain.
• In simple words, A list of organisms showing 'who eats whom' is called the food chain.
• The food can be transferred from one organism to the other through the food chain.
• Each step in the food chain is represented by a trophic level.
• Producers occupy the base of the food chain, producers are followed by Consumers → Secondary consumers → Tertiary consumers → Decomposers.

Explanation:

• Humans occupy the position of consumers in a food chain.
• The human can be divided into two types of consumers - Primary consumer & Secondary consumer.
• Primary Consumer - When humans derive their nutrition directly from the producers (green plants) in the form of fruits & vegetables.
• Secondary Consumer - When humans derive the nutrition indirectly by eating primary consumers like goat, cow & buffalo.

The correct answer is Fossil fuels.

Key Points

Non-Renewable Resources Examples

• Fossil Fuel
• Coal
• Rare earth elements
• Petroleum products
• Uranium

Thus, Fossil fuels are a non-renewable source of energy.

Additional Information 

Types of Renewable Energy

Solar Energy:

• ​The radiant light and heat energy from the sun is harnessed with the use of solar collectors.
• These solar collectors are of various types such as photovoltaics, concentrator photovoltaics, solar heating, (CSP) concentrated solar power, artificial photosynthesis, and solar architecture.
• This collected solar energy is then used to provide light, heat, and different other forms of electricity.

Wind Energy:

• The energy we get from winds is known as wind energy.
• For this, windmills have been used for hundreds of years to pump out water from the ground. We use large tall wind turbines that allow winds to generate electricity.
• The natural airflow on the surface of the earth is used to run the wind turbines.
• The most preferred locations for these wind turbines to be installed are the areas which and strong and have constant airflows on offshore and sites that are at high altitudes.

Hydroelectricity:

• According to statistics, hydroelectricity generated around 16.6% of the global energy resources and constituted about 70% of all the renewable electricity.
• This energy is another alternative source of energy that is generated by the construction of dams and reservoirs on the flowing water, the kinetic energy from the flowing water is used to run the turbines which generate electricity.
• Tidal power converts the energy of tides and Wave power which captures the energy from the surface of the ocean waves for power generation.
• These two forms of hydropower also have huge potential in electric power generation

Geothermal Energy:

• It is the energy that is generated from the thermal energy which is stored in the earth.
• The heat energy is captured on sources such as hot springs and volcanoes and this heat is directly used by industries for heating the water and other purposes.

Bio-Energy:

• This type of energy is derived from biomass which is a type of biological material derived from living organisms and plant-derived materials which are called lignocellulosic biomass.
• Biomass can be directly used via combustion to produce heat and indirectly it can be used to convert to biofuels.
• Biomass can be converted to other usable forms of energy such as transportation fuels like ethanol, biodiesel, and methane gas.

The computer has evolved from a large-sized simple calculating machine to a much smaller machine capable of multiple functionalities. Each generation of computer is designed based on the hardware technology used leading to better, cheaper and powerful computers that are faster and efficient than their predecessors.

Hence, it can be concluded from the table that vacuum tubes were used by the first generation computers.

All except 'Facebook' are name of search engine while 'Facebook' is the name of one of the social media.

Total number of people = 45

Position of A from the behind = 26^th

Position of A from the front = Total number of people – A’s position from the behind + 1

= 45 – 26 + 1

= 20^th