As per the given figure, two plates $A$ and $B$ of thermal conductivity $K$ and $2 K$ are joined together to form a compound plate. The thickness of plates are $4.0 \,cm$ and $2.5 \,cm$ respectively and the area of cross-section is $120 \,cm ^{2}$ for each plate. The equivalent thermal conductivity of the compound plate is $\left(1+\frac{5}{\alpha}\right) K$, then the value of $\alpha$ will be_______
$20$
$21$
$23$
$22$
Heat current is maximum in which of the following (rods are of identical dimension)
Ice formed over lakes has
hree rods of same dimensions are arranged as shown in figure they have thermal conductivities ${K_1},{K_2}$ and${K_3}$ The points $P$ and $Q$ are maintained at different temperatures for the heat to flow at the same rate along $PRQ$ and $PQ$ then which of the following option is correct
In the Arctic region, hemispherical houses called Igloos are made of ice. It is possible to maintain a temperature inside an Igloo as high as $20^{\circ} C$ because
For cooking the food, which of the following type of utensil is most suitable