At a given temperature,the pressure of an ideal gas of density $\rho$ is proportional to

Lactose is composed of .......

$A$ radioactive material decays by simultaneous emission of two particles with respective half-lives $1620 \, years$ and $810 \, years$. The time (in years) after which one-fourth of the material remains is:

Heartbeat increases due to the stimulation of .......

$2, 3$-dimethylhexane contains tertiary,secondary,and primary carbon atoms,respectively:

An electric dipole of length $4 \ cm$ is placed with its axis making an angle of $30^{\circ}$ to a uniform electric field of $10^6 \ N/C$. If it experiences a torque of $20 \sqrt{3} \ Nm$,then the potential energy of the dipole is: (in $J$)