Which of the following is not an antibiotic?

Heating $(NH_4)_2Cr_2O_7$ liberates a gas. The same gas is obtained by:

The temperature at which a real gas obeys ideal gas laws over an appreciable range of pressure is called:

In an atom,the order of increasing energy of electrons with quantum numbers $(i)$ $n=4, l=1$,$(ii)$ $n=4, l=0$,$(iii)$ $n=3, l=2$,and $(iv)$ $n=3, l=1$ is:

The equation of the plane passing through the point $(1,1,1)$ and perpendicular to the planes $2x+y-2z=5$ and $3x-6y-2z=7$ is:

$A$ metallic ring connected to a rod oscillates freely like a pendulum. If now a magnetic field is applied in a horizontal direction so that the pendulum now swings through the field,the pendulum will