What is inside the glass case of an incandescent bulb along with He-Ne gas ?

What is the use of glass bulb in an electric bulb? Can we use an electric bulb without the glass bulb in space?

A gas present in a cube of length 1 is shifted to another cube of length 21. What is the pressure of the gas in the 2nd case if the pressure of the gas in the 1st case is P at the same temperature?

An air bubble trapped inside a rectangular glass slab (cuboid) appear at 2 cm from one side and at 3 cm from the other opposite side. If the refractive index of glass is 1.5, what is the actual width of the glass slab?

Consider an ac circuit where an incandescent light bulb is in series with an inductor. If the frequency of generator is increased, what will happen to the brightness of bulb ?

The brightness of an incandescent light bulb is con- trolled by a regulator. The regulator is a variable resistor connected in series with the bulb. What happens to the colour of the light given off by the bulb as the resistance of the regulator is increased? What happens to the average energy of photons given out by the bulb? Does it increase?

What prevents the mercury level in the glass tube of a clinical thermometer from falling on its own when its bulb is removed from the mouth of a patient ?

A ray of light incident on an equilateral triangular glass prism of mu = sqrt(3) moves parallel to the base of the prism inside it. What is the angle of incidence for this ray ?