Two rods of same material have same length and area. The heat $\Delta Q$ flows through them for $12\, minutes$ when they are jointed in series. If now both the rods are joined in parallel, then the same amount of heat $\Delta Q$ will flow in …….. $\min$.

Two identical conducting rods are first connected independently to two vessels, one containing water at $100^o\ C$ and the other containing ice at $0^o\  C$. In the second case, the rods are joined end to end and connected to the same vessels. Let $q_1$ and $q_2\  g/s$ be the rate of melting of ice in the two cases respectively. The ratio $q_2/q_1$ is

Two rods $A$ and $B$ of same cross-sectional are $A$ and length $l$ connected in series between a source $(T_1 = 100^o C)$ and a sink $(T_2 = 0^o C)$ as shown in figure. The rod is laterally insulated  If $T_A$ and $T_B$ are the temperature drops across the rod $A$ and $B$, then 

The plots of intensity versus wavelength for three black bodies at temperature $T_1$, $T_2$ and $T_3$ respectively are as shown. Their temperatures are such that

Three copper blocks of masses $M_1, M_2$ and $M_3$ $kg$ respectively are brought into thermal contact till they reach equilibrium. Before contact, they were at $T_1, T_2, T_3(T_1> T_3)$. Assuming there is no heat loss to the surroundings, the equilibrium temprature $T$ is ($s$ is specific heat of copper)