$A$ car is moving with a speed of $72 ~km/h$ towards a hill. The car blows its horn at a distance of $1800 ~m$ from the hill. If the echo is heard after $10 ~s$,what is the speed of sound in $m/s$?

$A$ load of $1 ~kg$ weight is attached to one end of a steel wire of area of cross-section $3 ~mm^2$ and Young's modulus $10^{11} ~N/m^2$. The other end is suspended vertically from a hook on a wall,then the load is pulled horizontally and released. When the load passes through its lowest position,the fractional change in length is $(g = 10 ~m/s^2)$.

Boron forms covalent compounds due to:

In an adiabatic change,the pressure and temperature of a monoatomic gas are related as $P \propto T^C$,where $C$ equals

$A$ gas at $27 ^oC$ has a volume $V$ and pressure $P$. On heating, its pressure is doubled and volume becomes three times. The resulting temperature of the gas will be ....... $^oC$.

What is the electronic arrangement of a metal atom/ion in an octahedral complex with a $d^4$ configuration,if $\Delta_0 < P$ (pairing energy)?