The work done in placing a charge of $8 \times 10^{-18} \ C$ on a capacitor of capacitance $100 \ \mu F$ is:

Which of the following ions forms the most stable complex compound?

The rate constant,$k$,of a zero order reaction $2 NH_3(g) \xrightarrow[1130 \ K]{Pt} N_2(g) + 3 H_2(g)$ is $y \times 10^{-4} \ mol \ L^{-1} \ s^{-1}$. The rate of formation of hydrogen (in $mol \ L^{-1} \ s^{-1}$) is

$A$ gramophone record is revolving with an angular velocity $\omega$. $A$ coin is placed at a distance $r$ from the centre of the record. The static coefficient of friction is $\mu$. The coin will revolve with the record if

Which one of the following statements regarding helium is incorrect?

If $A$ is a non-zero square matrix of order $n$ with $\operatorname{det}(I+A) \neq 0$ and $A^3=O$,where $I$ and $O$ are the unit and null matrices of order $n \times n$ respectively,then $(I+A)^{-1}$ is equal to