The diagram shows the energy levels for an electron in a certain atom. Which transition shown represents the emission of a photon with the most energy?

With a standard rectangular bar magnet of length $l$,breadth $b$ $(b \ll l)$,and magnetic moment $M$,the time period of the magnet in a vibration magnetometer is $4 \ s$. If the magnet is cut normal to its length into four equal pieces,the time period (in seconds) with one of the pieces is:

The value of $x$,where $x>0$ and $\tan \left(\sec ^{-1}\left(\frac{1}{x}\right)\right)=\sin \left(\tan ^{-1} 2\right)$ is

The vector sum of two forces is perpendicular to their vector difference. In that case,the forces:

Which one of the following salts gives an acidic solution in water?

$A$ straight wire carrying current $i$ is turned into a circular loop. If the magnitude of the magnetic moment associated with it in $M.K.S.$ units is $M$,the length of the wire will be