Consider the following reaction:
$C_6H_5COCl \xrightarrow{H_2, Pd-BaSO_4} 'A'$
The product $'A'$ is:

If the harmonic mean of the roots of the equation $\sqrt{2}x^2 - bx + (8 - 2\sqrt{5}) = 0$ is $4$,then the value of $b$ is:

Identify the logic operation carried out by the following circuit.

If a body dropped freely from a height of $20 ~m$ reaches the surface of a planet with a velocity of $31.4 ~ms^{-1}$,then the length of a simple pendulum that ticks seconds on the planet is (in $~m$)

The intercepts on the $x$-axis made by tangents to the curve $y = \int_0^x |t| dt, x \in R$ which are parallel to the line $y = 2x$ are equal to:

Which of the following halides is most acidic?