During meiosis $I$,the chromosomes start pairing at

$A$ common-emitter amplifier is designed with a $n-p-n$ transistor $(\alpha = 0.99)$. The input impedance is $1 \, k\Omega$ and the load resistance is $10 \, k\Omega$. The voltage gain will be

The wavelength of the first line in the Balmer series in the hydrogen spectrum is $\lambda$. What is the wavelength of the second line?

$CsBr$ has $b.c.c.$ structure with edge length $4.3 \ \mathring{A}$. The shortest inter-ionic distance between $Cs^{+}$ and $Br^{-}$ is .............. $\mathring{A}$.

$CFCl_3$ is responsible for the decomposition of ozone to oxygen. Which of the following reacts with ozone to form oxygen?

$\tanh ^{-1}\left(\frac{1}{2}\right)+\operatorname{coth}^{-1}(2)$ is equal to