In the following common emitter circuit,if $\beta = 100$,$V_{CE} = 7\,V$,$V_{BE} = 0$,and $R_C = 2\,k\Omega$,then find the value of $I_B$ in $mA$.

Two masses of $10\,kg$ and $20\,kg$ respectively are connected by a massless spring as shown in the figure. $A$ force of $200\,N$ acts on the $20\,kg$ mass. At the instant when the $10\,kg$ mass has an acceleration of $12\,m/s^2$ towards the right,the acceleration of the $20\,kg$ mass is: (in $,m/s^2$)

Amongst $TiF_6^{2-}$,$CoF_6^{3-}$,$Cu_2Cl_2$ and $NiCl_4^{2-}$,the colourless species are:

The compound $CH_3-C(CH_3)=CH-CH_3$ on reaction with $NaIO_4$ in the presence of $KMnO_4$ gives :-

Which of the following statements are correct?
$(i)$ In prokaryotic cells,a special membranous structure formed by the extension of the plasma membrane into the cell is known as polysome.
$(ii)$ The smooth endoplasmic reticulum is the major site for synthesis of glycoproteins.
$(iii)$ $RuBisCO$ is the most abundant protein in the whole biosphere.
$(iv)$ Mitochondria,chloroplasts and peroxisomes are not considered as part of endomembrane system.
Of the above statements:

If the slope of one of the lines given by $ax^2+2hxy+by^2=0$ is two times the other,then: