Properties of Matter Questions

A $U$ tube with both ends open to the atmosphere, is partially filled with water. Oil, which is immiscible with water, is poured into one side until it stands at a distance of $10\text{mm}$ above the water level on the other side. Meanwhile the water rises by $65\text{mm}$ from its original level. The density of the oil is:

The bulk modulus of a spherical object is ‘$B$ ’. If it is subjected to uniform pressure ‘$p$ ’, the fractional decrease in radius is: