If R is outer radius and r is inner radius, then area of ring is ................. .

The difference between the outside and the inside surface area of a cylindrical pipe 14 cm long is 44 cm^2 . The pipe is made of 99 cm^3 of metal. If R is the outer radius and r is the inner radius of the pipe, then what is (R + r) equal to?

If the difference between the outer radius and the inner radius of a ring is 14 cm, then what is the difference between is outer circumference and innner circumference?

A steel ring is to be fitted on a wooden disc of radius R and thickness d. The inner radius of the ring is r which is slightly smaller than R. The outer radius of the ring is r + b and its thickness is d (same as the disc). There is no change in value of b and d after the ring is fitted over the disc, only the inner radius becomes R. If the Young’s modulus of steel is Y, calculate the longitudinal stress developed in it. Also calculate the tension force developed in the ring. [Take b lt lt r ]

1If r and R be the radii of inner and outer circles respectively,then area of ring is

A thin uniform disc (see figure) of mass M has outer radius 4R and inner radius 3R. The work required to take a unit mass for point P on its axis to infinity is

{:(,"Column A",,"Column B"),(18.,"If r and R be the radii of inner and outer circles, respectively, then area of a ring is _______.",(a),60),(19.,"The total surface area of a cube of edg" sqrt(10) "cm is ______." cm^(2).,(c ),pi (R^^(2)+r^(2))"sq. units"),(21.,"If the radius of the circule is 14 cm, then the area of the sector of angle." 45^(@) "is _______" cm^(2).,(d),pi(R^(2)-r^(2))"sq. units"),(,,(e ),sqrt(20)cm),(,,(f),77 cm^(2)):}

The slant height, outer radius and inner radius of a cone frustum are 2a cm, (a + b) cm and (a - b) cm. What is its curved surface area?

Consider two conducting wires of same length and material, one wire is solid with radius r. The other is a hollow tube of outer radius 2r while inner r. The ratio of resistance of the two wires will be -