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

The dispersive powers of the materials of two lenses forming an achromatic combination are in the ratio of $4: 3$. If the effective focal length of the two lenses is $+60 ~cm$,then the focal lengths of the lenses should be:

The major product in the following reaction is:

Potato and tomato are native of

If $n_1, n_2$,and $n_3$ are the fundamental frequencies of three segments into which a string is divided,then the original fundamental frequency $n$ of the string is given by

The product obtained at the anode when $50 \%$ $H_2SO_4$ aqueous solution is electrolysed using platinum electrodes is: