Let $f(x)=e^x$,$g(x)=\sin ^{-1} x$ and $h(x)=f(g(x))$,then $\frac{h^{\prime}(x)}{h(x)}$ is equal to

The $\Delta H^o$ of combustion of $C_4H_{10(g)}$ is $-2650 \ kJ \ mol^{-1}$. The amount of heat evolved at constant pressure that can be obtained by burning $5.8 \ kg$ of $C_4H_{10}$ is approximately:

What are the products formed when phenyl ethyl ether is heated with concentrated $HBr$?

In a chloroplast,chlorophyll is found in:

If three unit vectors $\overrightarrow{a}, \overrightarrow{b}, \overrightarrow{c}$ satisfy $\overrightarrow{a}+\overrightarrow{b}+\overrightarrow{c}=\overrightarrow{0}$, then the angle between $\overrightarrow{a}$ and $\overrightarrow{b}$ is

The value of $\left|\begin{array}{lll}1990 & 1991 & 1992 \\ 1991 & 1992 & 1993 \\ 1992 & 1993 & 1994\end{array}\right|$ is