The amount of work done in blowing a soap bubble such that its diameter increases from $d$ to $D$ is ($T$ = surface tension of solution).

If Henle's loop were absent from mammalian nephron,which of the following is to be expected?

Which one of the following frequencies of radiation (in $Hz$) has a wavelength of $600 \ nm$?

$A$ student has to answer $10$ out of $13$ questions in an examination,choosing at least $5$ questions from the first $6$ questions. The number of choices available to the student is:

Dimensions of a block are $1\,cm \times 1\,cm \times 100\,cm$. If the specific resistance of its material is $3 \times 10^{-7}\, \Omega \cdot m$, then the resistance between the opposite rectangular faces (the square ends) is:

Identify the product in the following reaction:
$Phenol + CHCl_3 + NaOH \rightarrow \text{Product}$