Two plates identical in size, one of black and rough surface (B_1) and the other smooth and polished (A_2) are in terconnected by a thin horizontal pipe with a mercury pellet at the centre. Two more plates A_1 (identical to A_2) and B_2 (identical B_1) are heated to the same temperature and placed closed to the plates B_1, and A_2 shown in Fig. The mercury pellet

Two plates identical in size, one of black and rough surface (B_1) a

1.	Two plates identical in size, one of black and rough surface (B_1) and the other smooth and polished (A_2) are in terconnected by a thin horizontal pipe with a mercury pellet at the centre. Two more plates A_1 (identical to A_2) and B_2 (identical B_1) are heated to the same temperature and placed closed to the plates B_1, and A_2 shown in Fig. The mercury pellet
Answer» moves to the right moves to the left remains stationary starts oscillating left and right Solution :Smooth and polished PLATES are poor radiators of heat. Hence, heat coming out from A is small, even though B being a black and rough plate is a good absorber. Effectively the heat coming to the left of pellet P is small. Black and rough plates are good radiators of heat. Hence plate `B_2` radiates heat to a satisfactory level , HOWEVER plate `A_2` being smooth and POLISHER, is a BAD absorber.Effectively the heat coming to the right of P is ALSO small.