One root of the equation $\cos x - x + \frac{1}{2} = 0$ lies in the interval

$A$ concave mirror of focal length $f$ produces an image $n$ times the size of the object. If the image is real,then the distance of the object from the mirror is:

What is the membrane surrounding the heart called?

The number of values of $x$ in the interval $[0, 5\pi]$ satisfying the equation $3\sin^2x - 7\sin x + 2 = 0$ is

Each category of taxonomic hierarchy is referred to as a unit of . . . . . . .

Adsorption of phenol from its aqueous solution on to fly ash obeys Freundlich isotherm. At a given temperature, from $10 \ mg \ g ^{-1}$ and $16 \ mg \ g ^{-1}$ aqueous phenol solutions, the concentrations of adsorbed phenol are measured to be $4 \ mg \ g ^{-1}$ and $10 \ mg \ g ^{-1}$, respectively. At this temperature, the concentration (in $mg \ g ^{-1}$ ) of adsorbed phenol from $20 \ mg \ g ^{-1}$ aqueous solution of phenol will be $.....$ .
Use : $\log _{10} 2=0.3$