$(\sim (p \vee q)) \vee (\sim p \wedge q)$ is logically equivalent to

The four distinct points $(0,0), (2,0), (0,-2)$ and $(k,-2)$ are concyclic,if $k$ is equal to

Consider the two following statements $A$ and $B$,and identify the correct choice given in the answers: $(A)$ Duddell's thermo galvanometer is suitable to measure direct current only. $(B)$ Thermopile can measure temperature differences of the order of $10^{-3} {}^{\circ}C$.

If a gas contains only three molecules that move with velocities of $100, 200, 500 \ ms^{-1}$. What is the $rms$ velocity of that gas in $ms^{-1}$?

$A$ coin and a six-faced die, both unbiased, are thrown simultaneously. The probability of getting a head on the coin and an odd number on the die is:

Two thin wire rings,each having a radius $R$,are placed at a distance $d$ apart with their axes coinciding. The charges on the two rings are $+q$ and $-q$. The potential difference between the centres of the two rings is