$I$ carried $1000\,kg$ of watermelon in summer by train. In the beginning,the water content was $99\%$. By the time $I$ reached the destination,the water content had dropped to $98\%$. The reduction in the weight of the watermelon was $.......\,kg$.

Out of $30$ points in a plane,$8$ of them are collinear. The number of straight lines that can be formed by joining these points is:

The value of $\int_{0}^{1} \tan ^{-1}\left(\frac{2 x-1}{1+x-x^{2}}\right) d x$ is

Pulses are a rich source of which of the following?

An inductor $(L = 100 \, mH)$,a resistor $(R = 100 \, \Omega)$,and a battery $(E = 100 \, V)$ are initially connected in series as shown in the figure. After a long time,the battery is disconnected by short-circuiting the points $A$ and $B$. The current in the circuit $1 \, ms$ after the short circuit is:

How many $mL$ of perhydrol is required to produce sufficient oxygen which can be used to completely convert $2 \ L$ of $SO_2$ gas to $SO_3$ gas (in $mL$)?