Which of the following is not hydrolysed?

The mean of four observations is $3$. If the sum of the squares of these observations is $48$,then their standard deviation is

The number of sigma $(\sigma)$ bonds in $but-1-ene$ is:

$A$ nichrome wire $50 \text{ cm}$ long and $1 \text{ mm}^2$ cross-section carries a current of $4 \text{ A}$ when connected to a $2 \text{ V}$ battery. The resistivity of the nichrome wire in $\Omega \cdot \text{m}$ is:

An $LCR$ series circuit with a resistance of $100\,\Omega$ is connected to an ac source of $200\,V$ (r.m.s.) and angular frequency $300\,rad/s$. When only the capacitor is removed,the current lags behind the voltage by $60^\circ$. When only the inductor is removed,the current leads the voltage by $60^\circ$. The average power dissipated is......$W$.

The wavelengths of electron waves in two orbits is $3: 5$. The ratio of kinetic energy of electrons will be