$A$ screen is placed $50\,cm$ from a single slit,which is illuminated with $6000 \mathring{A}$ light. If the distance between the first and third minima in the diffraction pattern is $3\,mm$,the width of the slit is.....$mm$.

An athlete completes one round of a circular track of radius $R$ in $40 \ s$. What will be his displacement at the end of $2 \ min \ 20 \ s$?

What is the volume (in litres) of oxygen required at $STP$ to completely convert $1.5 \ mol$ of sulphur into sulphur dioxide?

$A$ mass $M$,attached to a horizontal spring,executes $S.H.M.$ with amplitude $A_1$. When the mass $M$ passes through its mean position,a smaller mass $m$ is placed over it and both of them move together with amplitude $A_2$. The ratio of $\left( \frac{A_1}{A_2} \right)$ is

A linear octasaccharide $($molar mass $=1024 g mol ^{-1} )$ on complete hydrolysis produces three monosaccharides: ribose, $2-$deoxyribose and glucose. The amount of $2-$deoxyribose formed is $58.26 \%( w / w )$ of the total amount of the monosaccharides produced in the hydrolyzed products. The number of ribose unit$(s)$ present in one molecule of octasaccharide is $.....$
Use : Molar mass $($in g $mol ^{-1} )$: ribose $=150,2-$deoxyribose $=134$, glucose $=180$; Atomic mass $($in amu$): H =1, O =16$

Heat energy is incident on the surface at the rate of $1000 ~J/min$. If the coefficient of absorption is $0.8$ and the coefficient of reflection is $0.1$,then the heat energy transmitted by the surface in $5 ~min$ is: (in $~J$)