Hot water cools from $60\,^{\circ}C$ to $50\,^{\circ}C$ in the first $10\,min$ and to $42\,^{\circ}C$ in the next $10\,min$. The temperature of the surrounding is ......... $^{\circ}C$.

Cattle fed with spoilt hay of sweet clover which contains dicumarol:

Where are the constituent particles located in an end-centered unit cell?

Consider the set of all triangles $OPQ$ where $O$ is the origin and $P$,$Q$ are distinct points in the plane with non-negative integral coordinates $(x, y)$ such that $5x + y = 99$. The number of such distinct triangles whose area is a positive integer is:

$A$ wooden block, with a coin placed on its top, floats in water as shown in the figure. The distances $l$ and $h$ are shown. After some time, the coin falls into the water. Then:

In the given circuit,if point $C$ is connected to the earth and a potential of $+2000 \, V$ is applied to point $A$,what is the potential of point $B$ in volts?