When a body is taken from the pole to the equator,its weight:

The number of ways that $8$ beads of different colours can be strung as a necklace is

Four thin rods of same mass $M$ and same length $l$ form a square as shown in the figure. The moment of inertia of this system about an axis passing through the centre $O$ and perpendicular to its plane is

$A$ uniform cylinder of length $L$ and mass $M$ having cross-sectional area $A$ is suspended,with its length vertical,from a fixed point by a massless spring such that it is half submerged in a liquid of density $\sigma$ at equilibrium position. The extension $x_0$ of the spring when it is in equilibrium is:

When two sound sources of the same amplitude but of slightly different frequencies $v_1$ and $v_2$ are sounded simultaneously,the sound one hears has a frequency equal to

$A$ sound absorber attenuates the sound level by $20\, dB$. The intensity decreases by a factor of: