The Effective Atomic Number $(EAN)$ of $Co(CO)_4$ is $35$,hence it is less stable. It attains stability by:

Choose the incorrect statement from the following:
$S1:$ The efficiency of a heat engine can be $1$,but the coefficient of performance of a refrigerator can never be infinity.
$S2:$ The first law of thermodynamics is basically the principle of conservation of energy.
$S3:$ The second law of thermodynamics does not allow several phenomena consistent with the first law.
$S4:$ $A$ process,whose only result is to transfer heat from a colder to a hotter object,is impossible.

The displacement of a particle executing $SHM$ is given by $y=5 \sin \left(4 t+\frac{\pi}{3}\right)$. If $T$ is the time period and the mass of the particle is $2 \text{ g}$,the kinetic energy of the particle when $t=\frac{T}{4}$ is given by (in $J$)

The order and degree of the differential equation $\sqrt{\frac{dy}{dx}} - 4\frac{dy}{dx} - 7x = 0$ are

$A$ person in an elevator accelerating upwards with an acceleration of $2\,m s^{-2}$ tosses a coin vertically upwards with a speed of $20\,m s^{-1}$. After how much time will the coin fall back into his hand? $(g = 10\,m s^{-2})$

In the circuit shown in the figure,the current $I$ is: (in $\,A$)