The mass of the lift is 200 kg , when it ascends with an acceleration of $4 \mathrm{~m} / \mathrm{s}^2$ then the tension in the cable supporting the lift will be [Given: Acceleration due to gravity $g=10 \mathrm{~m} / \mathrm{s}^2$ ]

The average translational kinetic energy of nitrogen (molar mass 28) molecules at a particular temperature is 0.042 eV . The translational kinetic energy of oxygen molecules (molar mass 32) in eV at double the temperature is

A spring has a certain mass suspended from it and its period of vertical oscillations is $T_1$. The spring is now cut into two equal halves and the same mass is suspended from one of the halves. The period of vertical oscillations is now $\mathrm{T}_2$. The ratio of $T_2 / T_1$ is

The intensity ratio of the maxima and minima in an interference pattern produced by two coherent sources of light is $9: 1$. The intensities of the light sources used are in the ratio