Which of the following contains a coordinate covalent bond?

When $100 \, V$ $DC$ is applied across a solenoid,a current of $1 \, A$ flows in it. When $100 \, V$ $AC$ is applied across the same coil,the current drops to $0.5 \, A$. If the frequency of the $AC$ source is $50 \, Hz$,the impedance and inductance of the solenoid are:

Two rain drops reach the earth with different terminal velocities having ratio $9:4$. Then the ratio of their volumes is

$A$ projectile is fired at an angle of $45^\circ$ with the horizontal. The elevation angle of the projectile at its highest point as seen from the point of projection is:

Which of the following key factors makes a plasmid a suitable vector in genetic engineering?

At $298 \ K$,the value of $-\frac{\Delta[Br^-]}{\Delta t}$ for the reaction $5 Br^- (aq) + BrO_3^- (aq) + 6 H^+ (aq) \rightarrow 3 Br_2 (aq) + 3 H_2 O (l)$ is $x \ mol \ L^{-1} \ min^{-1}$. What is the rate (in $mol \ L^{-1} \ min^{-1}$) of this reaction?