$A$ body cools from $62^{\circ}C$ to $50^{\circ}C$ in $10 \text{ minutes}$ and to $42^{\circ}C$ in the next $10 \text{ minutes}$. The temperature of the surroundings is ........ $^{\circ}C$.

The area (in square units) of the triangle formed by $x+y+1=0$ and the pair of straight lines $x^2-3xy+2y^2=0$ is

The angle between the lines whose direction cosines are given by the equations $l^2+m^2-n^2=0$ and $l+m+n=0$ is

Phloem loading is related to:

$A$ rectangular loop has a sliding connector $PQ$ of length $l$ and resistance $R \, \Omega$. It is moving with a speed $v$ as shown. The setup is placed in a uniform magnetic field directed into the plane of the paper. The three currents $I_1$, $I_2$, and $I$ are:

The focal distance of a point on the parabola $y^2 = 16x$ whose ordinate is twice the abscissa,is