New Enroll in RBI Grade B New Batch - Starts on May 21

    Question

    A hollow cylinder is made up of steel. the difference in

    its outer and inner curved surface area is 132cm2.Height of cylinder is 21 cm and sum of the inner and outer radius is also 21 cm. Find the Total surface of the hollow cylinder.
    A 2904cm2 Correct Answer Incorrect Answer
    B 2304cm2 Correct Answer Incorrect Answer
    C 1756cm2 Correct Answer Incorrect Answer
    D 1331cm2 Correct Answer Incorrect Answer

    Solution

    We have -2 π h (R-r) = 132 = 2×22/7×21(R-r) =132 R-r = 1 Also given – R + r = 21 Then – R = 11cm, r = 10cm. So, the total surface of the hollow cylinder = 2 π h(R-r) +2 π (R2-r2) =2 π (R +r) [h +R-r] =2×22/7×21(21+1) =6×22×22 =2904cm2

    Practice Next

    Relevant for Exams: