Tag: applications of insulation

Questions Related to applications of insulation

Which of the following fabrics is preferred for winter garments ?

  1. Nylon

  2. Cotton

  3. Wool

  4. Silk


Correct Option: C
Explanation:

Wool is the fabric that is preferred for winter garments. As wool is bad conductor of heat. It insulates the body from the surrounding. And the air which is trapped in between the wool fibers; it prevents the flow of heat from our body to cool surrounding.

Which of the following is not a reason for using woolen clothes in Winter ?

  1. Wool is an insulator of heat.

  2. It traps a layer of air in its fabric.

  3. Air being an insulator doesn't allow body heat to escape into the atmosphere.

  4. All the above


Correct Option: D
Explanation:

Reason behind using woolen clothes during winter is that wool is the bad conductor of heat, it insulates the body from the surrounding. And the air which is trapped between woolen fabrics, prevents the flow of heat from the body as air is a bad conductor of heat too. So as a result the heat present in the body remains trapped in the body, it can't escape to atmosphere.

How does air trapped by the woolen fabric help ?

  1. Air is a good conductor of heat and allows warm air to come near body

  2. Air is a bad conductor of heat and allows body heat to escape into atmosphere

  3. Air is a bad conductor of heat and doesn't allow body heat to escape into atmosphere

  4. Air is a good conductor of heat and doesn't allow cool air to come near body.


Correct Option: C
Explanation:

Air trapped by the woolen fabric help us during winter. As air is bad conductor of heat and doesn't allow body heat to escape into atmosphere. The heat stored inside the body does not goes out as wool and air acts as a layer of insulator. And body heat is not escaped from the body.

When a metal conductor connected to left gap of a meter bridge is heated, the balancing point.

  1. Shifts towards right

  2. Shifts towards left

  3. Remains unchanged

  4. Remains at zero


Correct Option: A
Explanation:

When resistor is heated its resistance increases hence the balancing point will shift towards right.

Which of the following circular rods (given radius r and length l), each made of the same material and whose ends are maintained at the same temperature will conduct most heat?

  1. $r=r _0;l=l _0$

  2. $r=2r _0;l=l _0$

  3. $r=r _0;l=2l _0$

  4. $r=2r _0;l=2l _0$


Correct Option: B
Explanation:

Heat is given by $H=KA\Delta \theta _x=K\pi r^2 \dfrac{\Delta \theta} {l}$

For option B the value of $H$ will be more.

A shining metallic ball with a small black spot on its surface is heated to very high temperature and then quickly taken to a dark room. Then.

  1. Both appear equally bright

  2. The spot appears brighter than the ball

  3. The spot appears darker than the ball

  4. Both are invisible in the dark room


Correct Option: B

Which city is called the 'Manchester' of India?

  1. Jalandhar

  2. Ahmedabad

  3. Amritsar

  4. Sarnath


Correct Option: B
Explanation:

Ahmedabad.

Which city is called the Manchester of South India?

  1. Coimbatore

  2. Chitoor

  3. Hubli

  4. None of these


Correct Option: A
Explanation:

Coimbatore.

The first successful textile mill was established in Mumbai in the year _______.

  1. 1824

  2. 1854

  3. 1864

  4. 1884


Correct Option: B
Explanation:

1854.

Which one of the following places has woolen and silk textile industry combined?

  1. Varanasi

  2. Srinagar

  3. Mirzapur

  4. Agra


Correct Option: A
Explanation:

Varanasi.