In humans,which disorder is caused due to the absence of one of the $X$ chromosomes,i.e.,$45$ chromosomes with $XO$ genotype?

Molasses is a byproduct of which of the following?

Which one of the following orders is correct for the bond dissociation energies of halogen molecules?

In the circuit shown below $E_1 = 4.0 \, V$,$R_1 = 2 \, \Omega$,$E_2 = 6.0 \, V$,$R_2 = 4 \, \Omega$ and $R_3 = 2 \, \Omega$. The current $I_1$ is ............... $A$

The locus of the centre of a circle which passes through the origin and cuts off a chord of length $4$ units from the line $x=3$ is