Question

Figure shows two air-filled bulbs connected by a U-tube partly filled with alcohol. What happens to the levels of alcohol in the limbs $X$ and $Y$ when an electric bulb placed midway between the bulbs is lighted?

• A. The level of alcohol in limb $X$ falls while that in limb $Y$ rises
• B. The level of alcohol in limb $X$ rises while that in limb $Y$ falls
• C. The level of alcohol falls in both limbs
• D. There is no change in the levels of alcohol in either of the two limbs

Answer 1

The correct option is A The level of alcohol in limb $X$ falls while that in limb $Y$ rises

Black body absorbs and relases more heat, So, its x-side move vapours will be formed and due to this, in x-side alcohol level will fall due to vaporisation of acohol and pressure will also be increased and hence level of Y-side increases.

The level of alcohol in limb X falls while that in limb Y rises