Vitamin $B_{12}$ contains which of the following metals?

The length of the subtangent at any point of the curve $x^m y^n = a^{m+n}$ is proportional to -

The diagram below shows a hydraulic lift. $A$ force is applied at side $1$ and an output force is generated at side $2$. Which of the following is true?

Which of the following is a bactericidal antibiotic?

Let a random variable $X$ have a binomial distribution with mean $8$ and variance $4$. If $P(X \le 2) = \frac{k}{2^{16}}$,then $k$ is equal to

$A$ block rests on a rough inclined plane making an angle of $30^o$ with the horizontal. The coefficient of static friction between the block and the plane is $0.8.$ If the frictional force on the block is $10\,N,$ the mass of the block (in $kg$) is (take $g = 10\,m/s^2$)