A concrete sphere of radius `R` has cavity of radius `r` which is packed with sawdust. The specific gravities of concrete and sawdust are respectively `2.4 and 0.3` for this sphere to float with its entire volume submerged under water. Ratio of mass of concrete to mass of swadust will be

Inside a uniform sphere of mass M and radius R, a cavity of radius R//3 , is made in the sphere as shown :

If the radius of a sphere is 2r , them its volume will be

A uniform solid sphere of radius R has a cavity of radius 1m cut from it if centre of mass of the system lies at the periphery of the cavity then

The ratio of masses of a cubical block of wood and a chunk of concrete is 3/5 so that the combination just floats with entire volume submerged under water. If the specific gravity of wood is 0.5 then specific gravity of concrete will be

A sphere of radius 2R and mas M has a spherical cavity of radius R as shown in the figure. Find the value of gravitational field at a point P at a distance of 6R from centre of the sphere.

A conducting sphere of radius R_(2) has a spherical cavity of radius R_(1) which is non concentric with the sphere. A point charge q_(1) is placed at a distance r from the centre of the cavity. For this arrangement, answer the following questions. Electric potential at the centre of the cavity will be :

A conducting sphere of radius R_(2) has a spherical cavity of radius R_(1) which is non concentric with the sphere. A point charge q_(1) is placed at a distance r from the centre of the cavity. For this arrangement, answer the following questions. If q_(1) is shifted to the centre of the cavity, then: (choose the correct alternative)

A conducting sphere of radius R_(2) has a spherical cavity of radius R_(1) which is non concentric with the sphere. A point charge q_(1) is placed at a distance r from the centre of the cavity. For this arrangement, answer the following questions. Electric field (magnitude only) at the center of the cavity will be :

A non-conducting sphere of radius R is given a charge Q. Charge is uniformly distributed in its volume. The electric potential at centre and at the surface of sphere respectively are