During meiosis $I,$ the chromosomes start pairing at

All the springs in figures $(a)$,$(b)$,and $(c)$ are identical,each having a force constant $K$. The mass attached to each system is $m$. If $T_a, T_b$,and $T_c$ are the time periods of oscillations of the three systems respectively,then:

Five capacitors together with their capacitances are shown in the adjoining figure. The potential difference between the points $A$ and $B$ is $60 \, V$. The equivalent capacitance between the points $A$ and $B$ and the charge on the $5 \, \mu F$ capacitor will be respectively:

An open pipe of length $33 \ cm$ resonates to a frequency of $1000 \ Hz$. The mode of vibration is: (velocity of sound $= 330 \ m/s$)

$A$ sequence of how many nucleotides in messenger $RNA$ makes a codon for an amino acid?

An unpolarised light is incident at an interface of two dielectric media having refractive indices of $2$ (incident medium) and $2 \sqrt{3}$ (medium) respectively. To satisfy the condition that reflected and refracted rays are perpendicular to each other, the angle of incidence is . . . . . . .