Question

answer in one or two sentences. 1. how does convection current take place in air? 2. why digital thermometer is convenient to use these days? 3. what are conductors? write two examples. answer the following questions in detail. 1. how are land and sea breeze caused? 2. we wear woollen clothes in winter. explain. 3. explain with the help of an illustration three modes of heat transfer.

Explanation:

1. Convection in air occurs as warmer, less - dense air rises and cooler, denser air sinks, creating a continuous circulation.
2. Digital thermometers are convenient as they offer quick and accurate readings, are easy to read and sanitize.
3. Conductors are materials that allow heat or electricity to pass through them easily, like copper and aluminum. For the detailed questions:

• Land and sea breezes are caused by the differential heating of land and water. During the day, land heats up faster than water, causing air over land to rise and cooler air from the sea to flow in (sea - breeze). At night, the opposite occurs (land - breeze).
• We wear woollen clothes in winter because wool is a poor conductor of heat. It traps a layer of air between its fibers, which acts as an insulator, preventing heat loss from our body.
• The three modes of heat transfer are conduction (transfer of heat through direct contact, e.g., a metal rod heating up when one end is in a flame), convection (transfer of heat through the movement of fluids, like the air circulation above a hot stove), and radiation (transfer of heat in the form of electromagnetic waves, such as the heat we receive from the sun).

Answer:

1. Warmer, less - dense air rises, cooler, denser air sinks creating circulation.
2. Provide quick, accurate readings, easy to read and sanitize.
3. Materials allowing heat/electricity to pass easily; e.g., copper, aluminum.

Detailed:

1. Differential heating of land and water causes land and sea breezes.
2. Wool is a poor heat - conductor and traps air for insulation.
3. Conduction (direct contact), convection (fluid movement), radiation (electromagnetic waves).