Haploid plants are obtained from which of the following?

If the lines $x^2+2xy-35y^2-4x+44y-12=0$ and $5x+\lambda y-8=0$ are concurrent,then the value of $\lambda$ is

$A$ beam of light $AO$ is incident on a glass slab $(\mu = 1.54)$ in a direction as shown in the figure. The reflected ray $OB$ is passed through a Nicol prism. On viewing through the Nicol prism,we find on rotating the prism that:

Name the plant whose leaves are economically important and earn foreign exchange.

If $\int \frac{e^x-1}{e^x+1} d x=f(x)+c$,then $f(x)$ is equal to

The ratio of $C_p$ and $C_v$ of a gas $X$ is $1.4$. The number of atoms of the gas $X$ present in $11.2 \ L$ of it at $NTP$ will be: