The method of concentrating the ore which makes use of the difference in density between ore and impurities is called

$A$ wire of area of cross-section $10^{-6} \ m^2$ is increased in length by $0.1\%$. The tension produced is $1000 \ N$. The Young's modulus of the wire is:

$A$ man is standing on a balance and his weight is measured. If he takes a step to the left side,then his weight:

$A$ pendulum clock keeps correct time at $0\ ^oC$. The thermal coefficient of linear expansion of the material of the pendulum is $\alpha$. If the temperature rises to $t\ ^oC$,then the clock loses per day by (in seconds):

The equation of the common tangent of the parabolas $x^2 = 108y$ and $y^2 = 32x$ is

$\left(\frac{1+i}{1-i}\right)^4+\left(\frac{1-i}{1+i}\right)^4$ is equal to