When you are near an incandescent lamp, turn it on and off quickly. You feel its heat, but you find when you touch the bulb that it is not hot. Explain why you felt heat from the lamp.
@Abhisar

Question

When you are near an incandescent lamp, turn it on and off quickly. You feel its heat, but you find when you touch the bulb that it is not hot. Explain why you felt heat from the lamp.
@Abhisar

anonymous · Answer

you feel the heat because of the element inside the light bulb got warm when you turned it on

abhisar · Answer

ohkay let's see what actually happens !

abhisar · Answer

Bulbs or incandescent lamps are filled with inert gases. u know this ?

anonymous · Answer

oh ok

anonymous · Answer

so the gases heat up when turned on

abhisar · Answer

When we turn on the bulb, two things happen

abhisar · Answer

First,
Heat generaed directly reaches us via radiations

abhisar · Answer

Second,
Heat generated reaches the surface of bulb through convection

abhisar · Answer

Now,
Radiation is always faster than convection

anonymous · Answer

i see

abhisar · Answer

Since glass is transparent, it passes almost all the radiation and does not get heated by it

abhisar · Answer

Radiation is basically light !

abhisar · Answer

u getting these ?

anonymous · Answer

yes
Radiation caused by the inert gases from inside the bulb is created by convection

anonymous · Answer

is the light and therefore does not heat the glass of the bulb when turned on and off right away

abhisar · Answer

No No

anonymous · Answer

wait

anonymous · Answer

let me try again

abhisar · Answer

ok

anonymous · Answer

bulbs are filled with inert gases, two things happen when a bulb is turned on. generated heat reaches us through radiation and heat  reaches the surface of the bulb through convection. radiation is faster than convection. since glass in clear or transparent it passes almost all the radiation and doesn't get heated up by it.

abhisar · Answer

yes that's it

abhisar · Answer

To make it more understandable let's make it illustrative

abhisar · Answer

Suppose radiation is jet plane and convection is motor bike

abhisar · Answer

Now heat generated inside the bulb sits on jet plane to reach us

abhisar · Answer

and sits on motor bike to reach the glass surface

anonymous · Answer

ok that makes sense

anonymous · Answer

so what is your name?

abhisar · Answer

It's Abhisar
$\color{green}{\huge\ddot\smile}$

anonymous · Answer

where are you from?

abhisar · Answer

http://openstudy.com/users/abhisar

anonymous · Answer

cool

abhisar · Answer

$\color{green}{\huge\ddot\smile}$