Description : Weight of a person at a height of 2R from the centre of the earth, where R is the radius of the earth- (1) remains same (2) becomes half (3) becomes twice (4) becomes one-fourth
Last Answer : (4) becomes one-fourth Explanation: The gravitational force is proportional to 1/R2, where R is the distance from the centre of the Earth. So at a height of 2R from the centre of the earth, the corresponding weight would be one-fourth of the original weight.
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 : If three cylinders of radius r and height h are placed vertically such that the curved surface of each cylinder touches the curved surfaces -Maths 9th
Last Answer : hr2 (3-√−π2)(3−π2) The bases of the three cylinders when placed as given are as shown in the figure : Let the radius of the base of each cylinder = r cm. We are required to find the volume of air. ... ∠C = 60º) = 3 x 60o360o πr2=πr2260o360o πr2=πr22 ∴ Required volume = (3-√r2−π2r2)h=(3-√−π2)r2h.
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 right circular cone is 3 cm and its height is 4 cm. The curved surface of the cone will be (1) 12 sq. cm (2) 15 sq. cm (3) 18 sq. cm (4) 21 sq. cm
Last Answer : (2) 15 sq. cm
Description : . In case of turbulent flow of fluid through a circular pipe, the (A) Mean flow velocity is about 0.5 times the maximum velocity (B) Velocity profile becomes flatter and flatter with ... , shear stresses, random orientation of fluid particles and slope of velocity profile at the wall are more
Last Answer : (D) Skin friction drag, shear stresses, random orientation of fluid particles and slope of velocity profile at the wall are more
Description : A uniform thin rod of mass `m` and length `R` is placed normally on surface of earth as shown. The mass of earth is `M` and its radius `R`. Then the m
Last Answer : A uniform thin rod of mass `m` and length `R` is placed normally on surface of earth as shown. The mass of earth ... 2GMm)/R^(2)` D. `(4 GMm)/R^(2)`
Description : A proton moves in a uniform magnetic field in a circular path of radius R. If the energy of proton is doubled then the new radius becomes a) R √2 b) 2R c) R 2 d) √2 R
Last Answer : d) √2 R
Description : Velocity of escape is equal to A. r √(2g); where r: radius of Earth or any other planet for that matter, g: gravitational field strength B. g √(2r); where r: radius of ... (2gr); where r: radius of Earth or any other planet for that matter, g: gravitational field strength
Last Answer : √(2gr); where r: radius of Earth or any other planet for that matter, g: gravitational field strength
Description : Calculate the acceleration due to gravity at a height of 300 km from the surface of the Earth. (M = 5.98 × 10^24 kg, R = 6400 km).
Last Answer : Calculate the acceleration due to gravity at a height of 300 km from the surface of the Earth. (M = 5.98 × 1024 kg, R = 6400 km).
Description : Ten coulombs of positive charge are placed on an irregularly-shaped, solid piece of copper. Once the charge has stopped moving, the electric field inside the copper is: w) zero x) changes as one ... squared y) becomes smaller as you approach the center z) becomes larger as you approach the center
Last Answer : ANSWER: W -- ZERO
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 : Find the volume of cone of radius r/2 and height ‘2h’. -Maths 9th
Last Answer : Volume of cone = 1 / 3π × (r / 2)2 × 2h = 1 / 3π × r2 / 4 × 2h = 1 / 6 πr2h cu. units.
Description : if the slant height (l) of a cone is equal to the square root of the sum of the squares of radius (r) and height (h) then,
Last Answer : if the slant height (l) of a cone is equal to the square root of the sum of the squares of radius (r) and height (h) ... (2))` D. `r^(2)-h^(2)=l^(2)`.
Description : Frame the formula for the volume (v) of a cylinder given by the product of `pi`, square of radius (r) and height (h).
Last Answer : Frame the formula for the volume (v) of a cylinder given by the product of `pi`, square of radius (r) and height (h).
Description : A lamp is hanging along the axis of a circular table of radius r. at what height should the lamp be placed above the table so that the intensity of il
Last Answer : A lamp is hanging along the axis of a circular table of radius r. at what height should the lamp be placed ... is `(1)/(8)` of that at its centre ?
Description : What is the approximate height of a geostationary satellite from the surface of the earth? (1) 981 km (2) 15000 km (3) 35000 km (4) 55000 km
Last Answer : (3) 35000 km Explanation: A satellite in such an orbit is at an altitude of approximately 35,786 km (22,236 mi) above mean sea level.
Description : Curved surface area of a cone is 308 cm2 and its slant height is 14 cm. Find (i) radius of the base -Maths 9th
Last Answer : Slant height of cone, l = 14 cm Let the radius of the cone be r. (i) We know, CSA of cone = πrl Given: Curved surface area of a cone is 308 cm2 (308 ) = (22/7) r 14 308 = 44 r r = 308 ... Total surface area of cone = 308+(22/7) 72 = 308+154 Therefore, the total surface area of the cone is 462 cm2.
Description : If in a cylinder, radius is doubled and height is halved, then find its curved surface area. -Maths 9th
Last Answer : Let r and h be radius and height of the cyclinder, then C.S.A. = 2πrh Now, radius is doubled and height is halved. ∴ New radius = 2r and new height = h / 2 New C.S.A. = 2π × 2r × h / 2 = 2πrh .
Description : The weight of a body at the centre of earth is: (1) half the weight at the surface (2) zero (3) twice the weight at the surface (4) infinite
Last Answer : (2) zero Explanation: Weight of a body is the force with which it is attracted towards the centre of earth. The weight of a body, 'w' of mass `m' is given by: W = mg, where `g is the acceleration due ... of earth, value of 'g' is zero. Therefore, weight of a body is zero at the centre of the earth.
Last Answer : zero
Description : In the Earth, the weight of a body is maximum at the (1) North Pole(2) South Pole (3) Equator (4) Surface
Last Answer : Surface
Description : A spherical ball is divided into two equal halves. If the curved surface area of each half is 56.57 cm?, find the volume of the spherical ball.11531/cylinder-radius-halved-and-height-doubled-then-find-volume-with-respect-original-volume -Maths 9th
Last Answer : since curved surface of half of the spherical ball = 56.57 cm2 ∴ 2πr2 = 56.57 ⇒ r2 = 56.57 / 2 × 3.14 = 9 ⇒ r = 3 cm Now, volume of spherical ball = 4 / 3 πr3 = 4 / 3 × 3.14 × 3 × 3 × 3 = 113.04 cm3
Description : In a cylinder, radius is doubled and height is halved, then curved surface area will be -Maths 9th
Last Answer : The curved surface area will remain same. So, there is no change in the curved surface area of cylinder . Hence the curved surface area will remain same.
Description : For minimum curved surface area and given volume, the ration of the height and radius of base of a cone is :
Last Answer : For minimum curved surface area and given volume, the ration of the height and radius of base of a cone is : A. ` ... : 1` C. `1 : 2` D. None of these
Description : Whats the surface area of a can that has a radius of 4 and the height of 11?
Last Answer : 376.86 Units.
Description : A capillary tube is kept vertical in a beaker containing liquid. The height to which the liquid rises by capillary action is increased if (a) The radius of the capillary is large (b) The radius of the ... small (c) The density of the liquid is large (d) The surface tension of the liquid is small
Last Answer : Ans:(b)
Description : For a function given by F = 4x i + 7y j +z k, the divergence theorem evaluates to which of the values given, if the surface considered is a cone of radius 1/2π m and height 4π 2 m. a) 1 b) 2 c) 3 d) 4
Last Answer : b) 2
Description : A portion of an embankment having a uniform up-gradient 1 in 500 is circular with radius 1000 m of the centre line. It subtends 180° at the centre. If the height of the bank is 1 m at the lower end, and side slopes 2 ... earth work involved. (A) 26,000 m3 (B) 26,500 m3 (C) 27,000 m3 (D) 27,500 m
Last Answer : (D) 27,500 m3
Description : A thick wire of radius `r=5 mm` carries a steady current `I=10 A`. An electron leaves its surface perpendicularly with velocity `v_(0)=10^(6) m//s`. F
Last Answer : A thick wire of radius `r=5 mm` carries a steady current `I=10 A`. An electron leaves its ... from the surface of the wire before it turns back.
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 : 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 : Let angular value of one graduation of a tube of length be the radius of its internal curved surface, then (A) = x/206265 R (B) = R/206265 x (C) = 206265/x. R (D) = x. R/206265
Last Answer : (A) = x/206265 R
Description : If an object moves a circular distance ‘s’ of radius ‘r’, then it's angular displacement is A. s⁄r B. r⁄s C. rs D. r2s
Last Answer : s⁄
Description : The period of revolution of a certain planet in an orbit of radius R is T. Its period of revolution in an orbit of radius 4R will be:
Last Answer : 8 T
Description : If the radius of a simple curve is R, the length of the chord for calculating offsets by the method of chords produced, should not exceed. (A) R/10 (B) R/15 (C) R/20 (D) R/25
Last Answer : (C) R/20
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 : One end of a cylindrical rod is grounded to a hemispherical surface of radius`R=20mm`.It is immersed in water`(mu=4//3)`.If the refractive index of th
Last Answer : One end of a cylindrical rod is grounded to a hemispherical surface of radius`R=20mm`.It is immersed in water`(mu ... is ................(determine)
Description : What is The surface area of a sphere can be approximated as follows Surface area 4πr2 where r is the radius of the sphere π is a constant that is roughly equal to 3. Using the simple approximat?
Last Answer : 300 m^2
Description : A spherical porous catalyst particle of radius R is subjected to reactant A which reacts to form B by a zero order surface reaction A → B. Film mass transfer resistance is negligible and pore diffusion of A ... (D) Effectiveness factor for a zero order reaction cannot be 7/8 as it must always be 1
Last Answer : (A) Inner catalyst core of radius R/8 does not participate in reaction (
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 : When a detergent is added to pure water, its surface tension – (1) increases (2) decreases (3) remains constant (4) becomes infinite
Last Answer : (2) decreases Explanation: When Soaps and detergents are added to water, they weaken the strength of the skin on the water's surface due to surface tension by interfering with hydrogen bonding ... of the soap or detergent is also attracted to the water, thereby decreasing the surface tension.
Description : When a detergent is added to pure water, its surface tension (1) increases (2) decreases (3) remains constant (4) becomes infinite
Last Answer : decreases
Description : A particle is moving in a uniform circular motion with constant speed v along a circle of radius r. The acceleration-of the particle is – (1) zero (2) V/r (3) V/r² (4) V²/r
Last Answer : (4) V²/r Explanation: When a particle is moving in a uniform circular motion with constant speed and radius. the acceleration of the particle is given by v2/r. The particle will exhibit centripetal acceleration.