The equation of the directrix of the parabola ${y^2} + 4y + 4x + 2 = 0$ is

Which of the following is a bactericidal antibiotic?

Velocity and acceleration vectors of a charged particle moving perpendicular to the direction of a magnetic field at a given instant of time are $\overrightarrow{v}=2 \hat{i}+c \hat{j}$ and $\overrightarrow{a}=3 \hat{i}+4 \hat{j}$ respectively. Then the value of $c$ is

$A$ particle is performing simple harmonic motion along the $x$-axis with an amplitude of $4\, cm$ and a time period of $1.2\, s$. The minimum time taken by the particle to move from $x = 2\, cm$ to $x = +4\, cm$ and back again is given by .... $s$.

Which of the following is true in the case of an adiabatic process,where $\gamma = C_p / C_V$?

Which one of the following is not an iso-electronic pair?