Description : The semi-vertical angle of a cone remains constant. If its height increases by 2%, then find the approximate increase in its volume.
Last Answer : The semi-vertical angle of a cone remains constant. If its height increases by 2%, then find the approximate increase in its volume.
Description : From a circular plate of diameter 6 cm is cut out a circle whose diameter is a radius of the plate. Find the e.g. of the remainder from the center of circular plate (A) 0.5 cm (B) 1.0 cm (C) 1.5 cm (D) 2.5 cm
Last Answer : (A) 0.5 cm
Description : If there is a circular hole in a metal plate, what happens to the radius of the hole when the plate is heated? (1) Increases (2) Decreases (3) Unchanged (4) Depends upon the metal
Last Answer : (1) Increases Explanation: When a metal plate with a circular hole at its centre is heated, definitely along with the areal expansion of the plate the diameter of the circular hole also increases. Using ... of expansions, we find that the hole radius increases at the same linear rate as the metal.
Last Answer : Increases
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 : A joker’s cap is in the form of right circular cone of base radius 7 cm and height 24cm. Find the area of the sheet required to make 10 such caps. -Maths 9th
Last Answer : Radius of conical cap, r = 7 cm Height of conical cap, h = 24cm Slant height, l2 = (r2+h2) = (72+242) = (49+576) = (625) Or l = 25 cm CSA of 1 conical cap = πrl = (22/7)×7×24 = 550 CSA of 10 caps = (10×550) cm2 = 5500 cm2 Therefore, the area of the sheet required to make 10 such caps is 5500 cm2.
Description : Four equal sized maximum circular plates are cut off from a square sheet of area 784 cm2. What is the circumference of each plate? a) 22 cm b) 44 cm c) 42 cm d) 40cm
Last Answer : b) 44 cm
Description : The radius of a sphere is 8 cm and 0.02 cm is the error in its measurement. Find the approximate error in its volume.
Last Answer : The radius of a sphere is 8 cm and 0.02 cm is the error in its measurement. Find the approximate error in its volume.
Description : A copper plate has a circular hole cut in it. If the plate is heated to a higher temperature, the diameter of the hole (a) Becomes smaller (b) Increases (c) Remains constant (d) Increases but the total area of the plate remains constant
Last Answer : Ans:(b)
Description : What is the approximate circumference of a circle with 17.4 cm radius?
Last Answer : Circumference of circle: 2*pi*17.4 = 109 cm approximately
Description : What is the approximate percentage of earth coverage of a geostationary satellite at zero degree elevation? A. 33.3% B. 45.2% C. 42.5% D. 30.5%
Last Answer : C. 42.5%
Description : An electron moves in a circular orbit of radius 10 cm with a constant speed of `4.0xx10^(6) ms^(-1)`. Determine the electric current at a point on the
Last Answer : An electron moves in a circular orbit of radius 10 cm with a constant speed of `4.0xx10^(6 ... Determine the electric current at a point on the orbit.
Description : A circular coil of radius `10 cm "and" 100` turns carries a current 1A. What is the magnetic moment of the coil?
Last Answer : A circular coil of radius `10 cm "and" 100` turns carries a current 1A. What is the magnetic moment of the coil? A. ... 3,142 A-m^(2)` D. `3 A-m^(2)`
Description : A metal plate with a circular hole at the centre is heated. What will happen to the area of the hole? (1) Increase (2) Decrease (3) Remain constant (4) Will increase first and then decrease
Last Answer : (1) Increase Explanation: Assuming the disc is uniform and isotropic (the same in different directions), the hole will expand in the same ratio as the metal. It is because the thermal expansion equation ... is made out of metal. And if the circumference of the hole expands, so does the diameter.
Description : A metal plate with a circular hole at the centre is heated. What will happen to the area of the hole ? (1) Increase (2) Dacrease (3) Remain constant (4) Will increase first and then dcrease
Last Answer : Increase
Description : (i) The radius of a circle is increasing at the rate of 5 cm/sec. Find the rate of increasing of its perimeter. (ii) If the area of a circle increases
Last Answer : (i) The radius of a circle is increasing at the rate of 5 cm/sec. Find the rate ... to its circumference is iversely proportional to its radius.
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 : The radius and height of a right circular cone are 28cm & 72 cm respectively. Find its volume.
Last Answer : Answer: A
Description : The radius and height of a right circular cylinder are 42 cm & 63 cm respectively. Find its volume. a) 237564 cm3 b) 349272 cm3 c) 379252 cm3 d) 453213 cm3
Last Answer : Answer: B
Description : Find the radius of the largest right circular cone that can be cut out from a cube of edge 4.2 cm. -Maths 10th
Last Answer : Radius of the largest right circular cone 1/2 (Edge of the Square) =4.2/2 = 2.1 cm
Description : 30 circular plates, each of radius 14 cm -Maths 9th
Last Answer : Height of the cylinder formed (h) = 30 x 3 = 90 cm Radius of the base of the cylinder formed (r) = 14 cm (i) Total surface area of the cylinder = 2 πr(r + h) = 2 x 22/7 x 14(14 + 90) = 2 x 22/7 x 14 x 104 = 9152 cm2 (ii) Volume of the cylinder formed = πr2h = 22//7 x 14 x 14 x 90 = 55440 cm3
Description : A solid right circular cylinder of radius 8 cm and height 2 cm is melted and cast into a right circular cone of height 3 times that of the cylinder. -Maths 9th
Last Answer : Height of cone = 3 times height of cylinder = 3 3 = 9 cm Volume of cylinder = volume of cone r2 = 8 8 r = 8 cm l2 = h2 + r2 = (9)2 + (8)2 l = = 12 cm C.S.A (cone) = = 301.71 cm2
Description : The magnetic field due to a current carrying circular loop of radius 3 cm at a point on the axis at a distance of 4cm from the centre is `54muT`. What
Last Answer : The magnetic field due to a current carrying circular loop of radius 3 cm at a point on the axis at a distance of ... T` C. `125 mu T` D. `75 mu T`
Description : An electron is travelling at right angles to a uniform magnetic field of flux density 1.2 mT with a speed of 8 × 106 m s-1, the radius of circular path followed by electron is A. 3.8 cm B. 3.7 cm C. 3.6 cm D. 3.5 cm
Last Answer : 3.8 cm
Description : A circular shaft subjected to torsion undergoes a twist of 10in a length of 120 cm. If the maximum shear stress induced is limited to 1000 kg/cm2and if modulus of rigidity G = 0.8 x 106then the radius of the shaft should be (a) p/8 (b) p/27 (c) 18/p (d) 27/p
Last Answer : (d) 27/p
Description : On heating a circular metallic disc with a circular hole at the centre, the diameter of the hole will (a) decrease (b) remain the same (c) increase (d) first increase, then decrease
Last Answer : Ans:(c)
Description : Newton's rings experiment is performed with air gap between lens and plate. Now that gap is filled with water. What will be effect on radius (or diameter)? (a) Radius (or diameter) will remain ... or diameter) will increase (c) Radius (or diameter) will decrease (d) There will be no effect
Last Answer : (c) Radius (or diameter) will decrease
Description : A metal plate with a circular hole at the centre is heated. What will happen to the area of the hole?
Last Answer : Decrease
Description : The radius of a spherical balloon increases from 6 cm to 12 cm as air is being pumped into it. -Maths 9th
Last Answer : Surface area of a spherical balloon whose radius is 6 cm. = 4π × 6 × 6 cm2 Surface area of a spherical balloon whose radius is 12 cm. = 4π × 12 × 12 cm2 ∴ Ration of surface areas = 4π × 6 × 6 / 4π × 12 × 12 = 1 / 4 = 1 : 4
Description : The radius of a hemispherical balloon increases from 6 cm to 12 cm as air is being pumped into it. -Maths 9th
Last Answer : NEED ANSWER
Last Answer : Find the ratios of the surface areas of the balloon in the two cases.
Description : 50 circular plates each of radius .... Find its total surface area -Maths 9th
Last Answer : 50 circular plate diameter of plate =14cm Radius of plate = d/2=214=7cm thickness =0.5cm → Height of the cylinder = No. of plates × thickness of plate =50×0.5 =25cm → total surface Area = curved surface + 2 × area of base =2πr.h+2×πr2 =2πr(h+r) =2π×7(25+7) =2×722×7×32 =1408cm2
Description : A jet of water of cross-sectional area 20 sq. cm impinges on a plate at an angle of 60? with a velocity of 10 m/sec. Neglecting the friction between the jet and plate (density of water 1000/9.81 kgm-1 sec2 per cubic meter), the ... a.15 - 20 kg b.20 - 25 kg c.5 - 10 kg d.25 - 30 kg e.10 - 15 kg
Last Answer : a. 15 - 20 kg
Description : What is the approximate volume of a sphere with a radius of 12 units?
Last Answer : volume sphere = 4/3 πr³= 4/3 × π × 12³= 2304π≈ 7238 units³
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 : If yurt or circular tent has a radius of 3 meters What is the area of the floor of the yurt Use 3.14 for and pi .?
Last Answer : Floor area of circular tent: 3.14*3*3 = 28.26 square meters
Description : Hydraulic mean radius is A. Mean radius of sewer B. Difference in heads between two points in circular pipes C. Mean of radii in a pipe line of varying cross -sections D. Cross-sectional area/wetted perimeter
Last Answer : ANS: D
Description : If a circular grass lawn of 35 m in radius has a path 7 m wide running around it on the outside, then the area of the path is (a) 1450 m 2 (b) 1576 m 2 (c) 1694 m 2 (d) 3368 m 2
Last Answer : (c) 1694 m 2
Description : Find the total surface area of a hemisphere of radius 10 cm -Maths 9th
Last Answer : Radius of hemisphere, r = 10cm Formula: Total surface area of hemisphere = 3πr2 = 3×3.14×102 = 942 The total surface area of given hemisphere is 942 cm2.
Description : A spherical metal of radius 10 cm is melted and made into 1000 smaller spheres of equal sizes. In this process the surface area of the -Maths 9th
Last Answer : Option (C) is correct. Solution: Let the radius of the small spheres be r' cm. Volume of metal remains the same in both cases. So, vol of the spherical metal of radius 10 cm = total ... Total Surface area of 1000 smaller spheres: 1000*4π12 = 4000π Hence, the surface area increased by 10 times.
Description : Pick out the wrong statement. (A) Hammer crushers operate by impact action (B) Standard screens have circular opening (C) With increase in mesh number of screens, their diameter in microns decreases (D) 200 mesh screen has 200 openings per linear cm
Last Answer : (D) 200 mesh screen has 200 openings per linear cm
Description : In a 2-D CAD package, clockwise circular arc of radius, 5, specified from P1 (15,10)to P2 (10,15)will have its center at a.(10, 10) b.(15, 10) c.(15, 15) d.(10, 15)
Last Answer : a.(10, 10)
Description : For every 4°C raise in air inlet temperature of an air compressor, the power consumption will increases by_____ a) 2% b) 1% c) 3% d) 4%
Last Answer : b) 1%
Description : The surface of a spharical balloon is increase of its volume when its radius is 6 cm.
Last Answer : The surface of a spharical balloon is increase of its volume when its radius is 6 cm.
Description : The volume of a spherical balloon is increasing at a rate of ` 25 cm^(3)//sec`. Find the rate of increase of its curved surface when the radius of bal
Last Answer : The volume of a spherical balloon is increasing at a rate of ` 25 cm^(3)//sec`. Find the ... its curved surface when the radius of balloon is 5 cm.
Description : The rate of increase of the radius of an air bubble is 0.5 cm/sec. Find the rate o fincrease of its volume when the radius of air bubble is 2 cm.
Last Answer : The rate of increase of the radius of an air bubble is 0.5 cm/sec. Find the rate o fincrease of its volume when the radius of air bubble is 2 cm.
Description : Pick out the correct statement. (A) The slope of the stripping line is always less than unity (B) For a given separation in a binary distillation column, with increase in reflux ratio ( ... (D) Kremser-Brown-Souder's equation is used to calculate the efficiency of a plate tower
Last Answer : C) In Ponchon-Savarit method of no. of theoretical plate determination, the stripping and rectifying operating lines are vertical at total reflux
Description : Pick out the wrong statement. (A) In solvent extraction, the distribution co-efficient should be as large as possible for solvent economy (B) With increase in pressure, the solubility of ... in distillation column (D) The capacity of a distillation column is maximum at total reflux
Last Answer : (D) The capacity of a distillation column is maximum at total reflux
Description : The boundary layer thickness at a given section along a flat plate __________ with increasing Reynold's number. (A) Increases (B) Decreases (C) Remain same (D) May increase or decrease
Last Answer : (B) Decreases