Description : A right circular cylinder just encloses a sphere of radius r (see fig. 13.22). Find (i) surface area of the sphere, (ii) curved surface area of the cylinder -Maths 9th
Last Answer : Surface area of sphere = 4πr2, where r is the radius of sphere (ii) Height of cylinder, h = r+r =2r Radius of cylinder = r CSA of cylinder formula = 2πrh = 2πr(2r) (using value of h) = 4πr2 (iii) Ratio ... sphere)/CSA of Cylinder) = 4r2/4r2 = 1/1 Ratio of the areas obtained in (i) and (ii) is 1:1.
Description : Critical speed of rotation, N (in rps - rotation per second) of a trammel is equal to (where, g = acceleration due to gravity = 9.81 m/sec 2 and, r = radius of trammel, metre.) (A) (1/2π). √(g/r) (B) (1/π). √(g/r) (C) ½ √(g/r) (D) 2π. √(g/r)
Last Answer : (A) (1/2π). √(g/r)
Description : A square has its side equal to the radius of the sphere. The square revolves round a side to generate a surface of total area S. -Maths 9th
Last Answer : answer:
Description : Which of the following situations can be approximated to a steady state heat transfer system? (A) A red hot steel slab (having outside surface temperature as 1300°C) exposed to the atmospheric air at ... flowing at the rate of 6 Kg/minute through a copper pipe exposed to atmospheric air at 35°C
Last Answer : (B) 10 kg of dry saturated steam at 8 kgf/cm2 flowing through a short length of stainless steel pipe exposed to atmospheric air at 35°C
Description : The radius of gyration of a solid sphere of radius r is equal to a.0.8 r2 b.0.2 r2 c.0.3 r2 d.0.4 r2 e.0.5 r2
Last Answer : d. 0.4 r2
Description : A sphere is cut into two equal halves and both the halves are painted from all the sides. The radius of the sphere is r unit and the -Maths 9th
Description : Find the surface area of a sphere of radius: (i) 10.5cm (ii) 5.6cm (iii) 14cm -Maths 9th
Last Answer : Formula: Surface area of sphere (SA) = 4πr2 (i) Radius of sphere, r = 10.5 cm SA = 4 (22/7) 10.52 = 1386 Surface area of sphere is 1386 cm2 (ii) Radius of sphere, r = 5.6cm Using formula, SA = 4 (22 ... 75 cm Surface area of sphere = 4πr2 = 4 (22/7) 1.752 = 38.5 Surface area of a sphere is 38.5 cm2
Description : Find the ratio of surface area and volume of the sphere of unit radius. -Maths 9th
Last Answer : Required ratio = 4πr2 / 4/3.πr3 = 3 x 4 x π x (1)2 / 4 x π x (1)3 = 3/1 (Since, r = 1) i.e., 3 : 1
Description : Find the radius of a sphere whose surface area is 154 cm square. -Maths 9th
Last Answer : Let 'r' be the radius of sphere Surface area of sphere = 4 πr2 ⇒ 154 = 4 πr2 ⇒ 154 = 4 x 22/7 x r2 ⇒ r 2 = 154 x 7/4 x 22 = 49/4 ⇒ r = 7/2 cm = 3.5 cm
Description : The surface area of a sphere of radius 5 cm -Maths 9th
Last Answer : Radius of the sphere (r1) = 5 cm Radius of the base of cone (r2) = 4 cm Let r сm be the height of the cone. Surface area of sphere = 4 πr2 ⇒ 4 π(5)2 = 100 π cm2 Curved surface area of cone = πrl = 4 πl ... ∴ Volume of cone = 1/3 πr2h = 1/3 x 22/7 x 42 x 3 = 352/7 cm3 = 50.29 cm3 (Approximately)
Description : What is the surface area of a sphere with a 3 cm radius?
Last Answer : What is the surface area of a sphere with a 3 cm radius?
Description : The maximum acceleration of a particle moving with simple harmonic motion is ____. A. ω B. ω.r C. ω / 2 π D. 2 π / ω
Last Answer : B. ω.r
Description : The maximum acceleration of a particle moving with simple harmonic motion is ____. (A) ω (B) ω.r (C) ω / 2 π (D) 2 π / ω
Last Answer : (B) ω.r
Description : Which one of the following statements is correct? (A) (B) The cone subtended by an area on the sphere at the centre, is called the solid angle (C) The solid angle is equal to the ratio of the area on the sphere and the square of the radius of the sphere (D) All of these
Last Answer : Answer: Option D
Description : When a body moves with simple harmonic motion, the product of its periodic time and frequency is equal to A. Zero B. One C. π/2 D. 2π
Last Answer : B. One
Description : Ten coulombs of charge are placed on a solid copper sphere. Once the charge has come to rest, the ELECTRIC POTENTIAL inside the sphere is found to be: w) zero x) uniform inside the sphere and ... the sphere y) smaller than the electric potential outside the sphere z) varying as one over r squared
Last Answer : ANSWER: X -- UNIFORM INSIDE THE SPHERE AND EQUAL TO THE ELECTRIC POTENTIAL ON THE SURFACE OF THE SPHERE
Description : Five coulombs of charge are placed on a thin-walled conducting shell. Once the charge has come to rest, the electric potential inside the hollow conducting shell is found to be: w) zero x) uniform ... sphere y) smaller than the electric potential outside the sphere z) varying as one over r squared.
Last Answer : ANSWER: X -- UNIFORM INSIDE THE SPHERE AND EQUAL TO THE ELECTRIC OTENT
Description : A particle inside a hollow sphere of internal radius r with coefficient of friction 1/?3 can rest upto height of a.0.18 r b.0.435 r c.0.25 r d.0.134 r e.0.125 r
Last Answer : d. 0.134 r
Description : The moment of inertia of a solid sphere of radius r is a.Mr2 b.1/8 Mr2 c.2/3 Mr2 d.m4 e.1/2 Mr2
Last Answer : a. Mr2
Description : A sphere of radius r is cut from larger sphere of radius R. The distance between their centre is a. The centroid of the remaining valoume lies on the line of centres and the sistanc from the centre of the larger sphere is a.ar2 / (R2 - r2) b.107 dynes c.aR/(R2-r2) d.aR/(R - r) e.ar3 / (R3 - r3)
Last Answer : e. ar3 / (R3 - r3)
Description : In Fig., a right circular cylinder just encloses a sphere of radius r. Find -Maths 9th
Last Answer : (i) Surface areas S1 of the sphere = 4 πr2 (ii) We have Radius of the cylinder = r Height of the cylinder = h = 2r ∴ Curved surface area S2 of the cylinder ... 2 πrh = 2 πr x 2r = 4 πr2 (iii) S1/S2 = 4 πr2/4 πr2 = 1/1 ∴ S1 : S2 = 1 : 1
Description : A uniform solid sphere of radius R has a hole of radius R/2 drilled inside it. One end of the hole is at the centre of the sphere
Last Answer : A uniform solid sphere of radius R has a hole of radius R/2 drilled inside it. One end ... boundary. Locate centre of mass of the remaining sphere.
Description : What reflecting surface forms a geometrically perfect image of a point source located at infinity (such as that approximated by a star)? w) Paraboloid x) Ellipsoid y) spherical z) Hyperboloid
Last Answer : ANSWER: W -- PARABOLOID
Description : Frame the formula: The lateral surface area of a cylinder S is equal to twice the product of `pi`, radius (r) and height (h) of the cylinder.
Last Answer : Frame the formula: The lateral surface area of a cylinder S is equal to twice the product of `pi`, radius (r) ... `S=pirh` C. `2S=pirh` D. `S=2pirh`
Description : if seve times the curved surface area (A) of a cylinder is equal to 44 times the proudct of base radius (r) and height (h) then what si the formula wi
Last Answer : if seve times the curved surface area (A) of a cylinder is equal to 44 times the proudct of base ... (h) then what si the formula with subject A?
Description : The radius of a sphere decreases from 10 cm to `9.9` cm. Find (i) approximate decrease in its volume. (ii) approximate decrease in its surface.
Last Answer : The radius of a sphere decreases from 10 cm to `9.9` cm. Find (i) approximate decrease in its volume. (ii) approximate decrease in its surface.
Description : Fig shows a small air bubble inside a glass sphere `(mu = 1.5)` of radius 10 cm. the bubble is 4.0 cm below the surface and is viewed normally from th
Last Answer : Fig shows a small air bubble inside a glass sphere `(mu = 1.5)` of radius 10 cm. the ... from the outside. Find the apparent depth of the bubble.
Description : An object is placed `50 cm` from the surface of a glass sphere of radius `10 cm` along the diameter. Where will the final image be formed after refrac
Last Answer : An object is placed `50 cm` from the surface of a glass sphere of radius `10 cm` along the diameter. ... both the surfaces ? `mu` of glass `=1.5`.
Description : A hollow METALLIC sphere has an inner radius A and an outer radius B. If charge is placed on the inner surface, that is at radius A, where is the charge located after it has come to rest?
Last Answer : ANSWER: ON THE SPHERE'S OUTER SURFACE or OUTSIDE RADIUS B
Description : If is the length of a sub-chord and is the radius of simple curve, the angle of deflection between its tangent and sub-chord, in minutes, is equal to (A) 573 S/R (B) 573 R/S (C) 1718.9 R/S (D) 1718.9 S/R
Last Answer : (D) 1718.9 S/R
Description : A sphere and a right circular cone of same radius have equal volumes. By what percentage does the height of the cone exceed its diameter ? -Maths 9th
Description : If the volume of a sphere is numerically equal to its surface area, then find the diameter of the sphere. -Maths 9th
Last Answer : Let r be the radius of the sphere. and Volume of a sphere = surface area of the sphere ⇒ 4 / 3πr3 = 4πr2 ⇒ r = 3 cm ∴ Diameter of the sphere = 2r = 2 × 3 = 6 cm
Description : A disc of radius R rotates with constant angular velocity `omega` about its own axis. Surface charge density of this disc varies as `sigma = alphar^(2
Last Answer : A disc of radius R rotates with constant angular velocity `omega` about its own axis. Surface charge density of ... D. `(mu_(0)alphaomegaR^(3))/(3)`
Description : In case of laminar flow of fluid through a circular pipe, the (A) Shear stress over the cross-section is proportional to the distance from the surface of the pipe (B) Surface of velocity distribution is a ... occurs at a radial distance of 0.5 r from the centre of the pipe (r = pipe radius)
Last Answer : (B) Surface of velocity distribution is a paraboloid of revolution, whose volume equals half the volume of circumscribing cylinder
Description : The curved surface area of a right circular cylinder of height 14 cm is 88 cm2. Find the diameter of the base of the cylinder. (Assume π =22/7 ) -Maths 9th
Last Answer : Height of cylinder, h = 14cm Let the diameter of the cylinder be d Curved surface area of cylinder = 88 cm2 We know that, formula to find Curved surface area of cylinder is 2πrh. So 2πrh =88 cm2 (r is the ... 88 cm2 2r = 2 cm d =2 cm Therefore, the diameter of the base of the cylinder is 2 cm.
Description : For spheres, the surface shape factor is given by (where, A = area, V = volume, and D = diameter) (A) π = (A/D2 ) (B) π/6 = (V/D3 ) (C) AD/V (D) None of these
Last Answer : (A) π = (A/D2 )
Description : An object moving in a circle of radius ‘r’ with a constant speed ‘v’ has a constant acceleration towards the center equal to A. v²⁄r B. v⁄r C. v²×r D. v×r
Last Answer : v²⁄r
Description : The total surface area of a cone whose radius is r/2 and slant height 2l is -Maths 9th
Last Answer : Total surface area of cone = πr(r+l) Given, radius = r/2 and slant height = 2l Therefore, new total surface area of cone = πr/2(r/2+2l) = π(r/4^2+rl) = πr(l+r/4)
Last Answer : Radius (r)=r/2 & slant height=2l TSA (S)=PIE R (l+r) =22/7×r/2(2l+r/2) =11/7×r(2l+r/2)
Description : The maximum value of hoop compression in a dome is given by (A) wR / 4d (B) wR/2d (C) wR/d (D) 2wR/d Where, w = load per unit area of surface of dome R = radius of curvature d = thickness of dome
Last Answer : (B) wR/2d
Description : An R.C.C. beam not provided with shear reinforcement may develop cracks in its bottom inclined roughly to the horizontal at (A) 25° (B) 35° (C) 45° (D) 55°
Last Answer : Answer: Option C
Description : In case of solid disk flywheel, the mass (m) of disk is given by (A) πR 2 tρ (B) (π/2)R 2 tρ (C) 3πR 2 tρ (D) (3/2)πR 2 tρ
Last Answer : (A) πR 2 tρ
Description : If the potential is given by, V = 10sin θ cosφ/r, find the density at the point P(2, π/2, 0) (in 10 -12 units) a) 13.25 b) 22.13 c) 26.31 d) 31.52
Last Answer : b) 22.13
Description : Compute divergence theorem for D = 5r 2 /4 i in spherical coordinates between r = 1 and r = 2 in volume integral. a) 80 π b) 5 π c) 75 π d) 85 π
Last Answer : c) 75 π
Description : Evaluate Gauss law for D = 5r 2 /4 i in spherical coordinates with r = 4m and θ = π/2 as volume integral. a) 600 b) 588.9 c) 577.8 d) 599.7
Last Answer : b) 588.9
Description : Evaluate Gauss law for D = 5r 2 /4 i in spherical coordinates with r = 4m and θ = π/2. a) 600 b) 599.8 c) 588.9 d) 577.8
Last Answer : c) 588.9
Description : Transform the spherical system B = (10/r)i + (10cos θ)j + k into cylindrical form at (5, π/2, -2) a) 2.467i + j + 1.167k b) 2.467i – j + 1.167k c) 2.467i – j – 1.167k d) 2.467i + j – 1.167k
Last Answer : a) 2.467i + j + 1.167k
Description : A sphere and a cone have equal bases. If their heights are also equal, the ratio of their curved surface will be : -Maths 9th
Description : Statistics question: a binomial model can be approximated with what other model?
Last Answer : Normal distribution?