A stone breaks the window glass into pieces, while a bullet pierces through the same. Why?

Will current flow more easily through a thick wire or a thin wire of the same material, when connected to the same source? Why?

Explain why white light is dispersed while passing through a prism.

Explain why Water on a clean glass surface tends to spread out while mercury on the same surface tends to form drops. (Put differently, water wets glass while mercury does not.)

Explain why: n optical pyrometer (for measuring high temperatures) calibrated for an ideal black body radiation gives too low a value for the temperature of a red hot iron piece in the open, but gives a correct value for the temperature when the same piece is in the furnace

Explain why (a) The angle of contact of mercury with glass is QBtuse, while that of water with glass is acutue

Why does a piece of red glass when heated and taken out glow with green light?

Explain why a ray of light passing through the centre of curvature of a concave mirror gets reflected along the same path after reflection.

Calculate the rate of loss heat through a glass window of area 1000sq.cm. and thickness 4mm when the temperature inside is 37°C and outside is 5°C ( K for glass =0.0022)

Why is +2 oxidation state of manganese quite stable while the same is not true for iron?