Question

Give reason for the following :
(a) Cooking utensils are made of metals.
(b) Pressure cooker is provided with bakelite handle.
(c) Air conditioned buildings have double-walled windows.
(d) False ceiling keeps the room warm during winters.
(e) Asbestos sheets are preferred over iron sheets for rooing​

Answer 1

$\huge \tt \underline \orange {Answer}$

$\bf\pink{Cooking \: utensils \: are \: made \: of \: metals.}$

$\red \longrightarrow$ Cooking utensils are made of metals because, metals are good conductor of heat, and for cooking food heat energy is required, and metal in utensils, they are cooked more easily.

$\bf\orange{Pressure \: cooker \: is \: provided \: with \: Bakelite \: handle.}$

$\red \longrightarrow$ Handles of Pressure cookers are made with Bakelite as are poor conductor of heat, and they prevent heat to flow through them, so we can hold the cooker easily.

$\bf\purple{Air \: conditioned \: buildings \: have \: double-walled \: windows.}$

$\red \longrightarrow$ Air conditioned building have double wallled windows, as it prevents head to come inside the room and maintain the temperature of it, keeping the room cool.

$\bf\green{False \: ceiling \: keeps \: the \: room \: warm \: during \: winters.}$

$\red \longrightarrow$ Air, being a bad conductor of heat, gets trapped and resulting in the warmth of room in winter's.

$\bf\blue{Asbestos \: sheets \: are \: preferred \: over \: iron \: sheets \: for \: rooing.}$

$\red \longrightarrow$ Asbestos is an insulator and so does opposite jobs, it keeps the room warm in winters and cool in summers.

Answer 2

$\rm\purple{ Cooking \:utensils\: are\: made \:of\: metals:-}$

✓ Cooking utensils are made up of metals as they conduct heat easily and quickly. This property helps us to cook food in it. Metals such as aluminium , steel , etc. are used for making cooking utensils.

$\rm\green{ Pressure \: cookers \: are\: provided \: with \: bakelite \: handle}$

✓ Bakelite is a type of plastic which has no effect of heat on itself . It means that it won't melt when heated. We know that plastic is a bad conductor or an insulator.

As we have discussed above ; metals are good conductors of heat and they allow the electrons to pass through them which make the whole surface of the utensil to get hot. When a hot substance is caught; it may burn the skin . So, to prevent the burning of skin ; bakelite handles are fit.

$\rm\pink{ Air \: Conditioned \: buildings\: have \:double\: walled\: windows.}$

✓Air conditioned buildings have double walled windows as the air which is trapped in the gap between the two glass slides /windows act as bad conductor or insulator for heat which comes from outside so that the inside of the room is cool.

Thermos or flasks also follow the same theory to keep the substance inside either hot or cold.

$\rm\red{False \: ceilings\: keep \: the\: room \:warm\: during \:winters}$

✓We know that air is a gas. Gases transfer heat through convection. When false ceilings are put up ; they prevent the air to pass it's heat downwards ; thus keeping the room warm.

$\rm\orange{ Asbestos\: sheets \:are \:preferred\: over\: iron\: sheets \:for \:roofing}$

✓Iron which is a metal ; conducts heat which may be a good thing for winters but a very bad one in summers. Hence , asbestos which is an insulator is used . It keeps the room beneath cool in summers and warm in winters.