Activity 14.2 NCERT Class 10 Science, Sources of Energy

Activity 14.2 NCERT Class 10 Science, Sources of Energy

Brief procedure:

Activity 14.2 asks us to 1. choose a good fuel for cooking in various condition; 2.give reasons for that and classify them.

Answer:

Various fuel options for cooking food for us are:

Electricity, LPG, Wood, Coal, solar cooker, etc.

In the home we prefer LPG and electricity as they are highly efficient, does not cause smoke, and are easy to use.

Good fuel is a fuel which is easily available, cheap, clean, and easy to use.

Criteria to classify fuel:

We classify fuels based on many criteria like;

State of fuel: Solid, liquid, gas.

Ease of use: Easy to handle, hard to handle. Here electricity and LPG are easy to handle while using wood is cumbersome.

Economy: Cheap vs costly fuels. eg. Coal vs petrol.

Pollution: Clean fuel vs polluting fuel. Electricity, solar cooker, LPG are clean fuels, as they do not produce smoke while wood and coal fall in the second category.

Choice of fuel in different conditions:

A. In a forest: In the forest, we can not have electricity or transport gas cylinder. In such places, woods from the forest is easy to procure.

B. In a remote mountain village or small island:

Here also we can not get electricity or LPG connection. Since this is a mountainous region or island. Here we can easily get enough solar energy, so, we can use a solar cooker in such places.

C. New Delhi:

In a big city like Delhi, Mumbai electricity and LPG connection are available with good service. So we prefer them to cook our food. In Delhi, electricity is cheap so the use of electrical appliances like induction or heater incurs a lesser cost.

D. Lived five centuries ago: 

A century has a life span of 100 years. Presently we live in the 21st century. In the 16th century (1500-1599 AD) there was no fossil fuel, LPG or electricity. Peoples of 16th century cooked food in a clay stove using the energy of wood, coal and cow dung cake.

How are factors different in each case:

In each of the given situation, we first look for the availability of various fuel options. For example in forest wood is the only option to cook food. If more than one options are available, we use an easy to use and clean fuel. For example, in homes, we use LPG which is easy to use fuel and does not produce smoke. If all the available options are easy to use and clean we look for the cost factor, efficiency and other measures.

Next: Thermoelectric production of electricity using a dynamo and turbine. Activity 14.3.

See also: Differences between forms of energy and sources of energy. Activity 14.1.