The critical radius 'r' of insulation on a pipe is given by (A) r = 2k/h (B) r = k/h (C) r = k/2h (D) r = h/k

The critical radius 'r' of insulation on a pipe is given by

(A) r = 2k/h

(B) r = k/h

(C) r = k/2h

(D) r = h/k

by

1 Answer

Answer :

(B) r = k/h

by

Related questions

The critical radius of insulation for cylindrical pipe is (where, hi = heat transfer coefficient at inside of the pipe) (A) K/h0 (B) 2K/h0 (C) hi /K (D) 2hi /K

Description : The critical radius of insulation for cylindrical pipe is (where, hi = heat transfer coefficient at inside of the pipe) (A) K/h0 (B) 2K/h0 (C) hi /K (D) 2hi /K

Last Answer : (A) K/h0

The critical radius of insulation for a spherical shell is (where, K = thermal conductivity of insulating material h0 = heat transfer coefficient at the outer surface) (A) K/h0 (B) 2K/h0 (C) h0 /K (D) h0 /2K

Description : The critical radius of insulation for a spherical shell is (where, K = thermal conductivity of insulating material h0 = heat transfer coefficient at the outer surface) (A) K/h0 (B) 2K/h0 (C) h0 /K (D) h0 /2K

Last Answer : (B) 2K/h0

Given B= (10/r)i+( rcos θ) j+k in spherical coordinates. Find Cartesian points at (- 3,4,0) a) -2i + j b) 2i + k c) i + 2j d) –i – 2k

Description : Given B= (10/r)i+( rcos θ) j+k in spherical coordinates. Find Cartesian points at (- 3,4,0) a) -2i + j b) 2i + k c) i + 2j d) –i – 2k

Last Answer : a) -2i + j

A recursive function h, is defined as follows: h(m)=k, if m=0 = 1, if m=1 = 2h(m-1) + 4h(m-2), if m≥2 If the value of h(4) is 88 then the value of k is: (1) 0 (2) 1 (3) 2 (4) -1

Description : A recursive function h, is defined as follows: h(m)=k, if m=0  = 1, if m=1 = 2h(m-1) + 4h(m-2), if m≥2 If the value of h(4) is 88 then the value of k is: (1) 0 (2) 1 (3) 2 (4) -1

Last Answer : (3) 2 

Find the volume of cone of radius r/2 and height ‘2h’. -Maths 9th

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.

Find the volume of cone of radius r/2 and height ‘2h’. -Maths 9th

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.

State the formula for acceleration due to gravity at depth ‘d’ and altitude ‘h’ Hence show that their ratio is equal to ((R - d)/(R - 2h))

Description : State the formula for acceleration due to gravity at depth ‘d’ and altitude ‘h’ Hence show that their ratio is equal to ((R - d)/(R - 2h))

Last Answer : State the formula for acceleration due to gravity at depth d' and altitude h' Hence show that ... small as compared to the radius of the Earth.

What is the critical radius of insulation (cms) for a metallic cylinder, if the convective heat transfer co-efficient with the ambient atmosphere is 5 W/m2. °K? Thermal conductivity of metal and insulation material are 40 and 0.1 W/m.°K respectively. (A) 2 (B) 8 (C) 10 (D) 40

Description : What is the critical radius of insulation (cms) for a metallic cylinder, if the convective heat transfer co-efficient with the ambient atmosphere is 5 W/m2. °K? Thermal conductivity of metal and insulation material are 40 and 0.1 W/m.°K respectively. (A) 2 (B) 8 (C) 10 (D) 40

Last Answer : (A) 2

Upto the critical radius of insulation, added insulation, will (A) Increase the heat loss (B) Decrease heat loss and will have no effect beyond that (C) Decrease heat flux (D) Reduce convection heat loss compared to conduction heat less

Description : Upto the critical radius of insulation, added insulation, will (A) Increase the heat loss (B) Decrease heat loss and will have no effect beyond that (C) Decrease heat flux (D) Reduce convection heat loss compared to conduction heat less

Last Answer : Option B

According to Bohr's theory of hydrogen atom, the angular momentum of the electron in the fourth orbit is given by (a) h/2p (b) 4h/p (c) h/p (d) 2h/p

Description : According to Bohr's theory of hydrogen atom, the angular momentum of the electron in the fourth orbit is given by (a) h/2p (b) 4h/p (c) h/p (d) 2h/p

Last Answer : Ans:(d)

The magnetic energy of a magnetic material is given by a) BH/2 b) B/2H c) H/2B d) B/H

Description : The magnetic energy of a magnetic material is given by a) BH/2 b) B/2H c) H/2B d) B/H

Last Answer : a) BH/2

The equation of a parabolic arch of span and rise , is given by (A) y = h/l² × (1 - x) (B) y = 2h/l² × (1 - x) (C) y = 3h/l² × (1 - x) (D) y = 4h/l² × (1 - x)

Description : The equation of a parabolic arch of span and rise , is given by  (A) y = h/l² × (1 - x)  (B) y = 2h/l² × (1 - x)  (C) y = 3h/l² × (1 - x)  (D) y = 4h/l² × (1 - x) 

Last Answer : (D) y = 4h/l² × (1 - x) 

Heat transfer co-efficient (h) for a fluid flowing inside a clean pipe is given by h = 0.023 (K/D) (DVρ/µ) 0.8 (CP .µ/k) 0.4 . This is valid for the value of NRe equal to (A) < 2100 (B) 2100-4000 (C) > 4000 (D) > 10000

Description : Heat transfer co-efficient (h) for a fluid flowing inside a clean pipe is given by h = 0.023 (K/D) (DVρ/µ) 0.8 (CP .µ/k) 0.4 . This is valid for the value of NRe equal to (A) < 2100 (B) 2100-4000 (C) > 4000 (D) > 10000

Last Answer : (D) > 10000

For a given material, if E, C, K and m are Young's modulus, shearing modulus, bulk modulus and Poisson ratio, the following relation does not hold good (A) E = 9KC/3K + C (B) E = 2K (1 + 2/m) (C) E = 2C (1 + 1/m) (D) E = 3C (1 - 1/m)

Description : For a given material, if E, C, K and m are Young's modulus, shearing modulus, bulk modulus and Poisson ratio, the following relation does not hold good (A) E = 9KC/3K + C (B) E = 2K (1 + 2/m) (C) E = 2C (1 + 1/m) (D) E = 3C (1 - 1/m)

Last Answer : (C) E = 2C (1 + 1/m)

The relationship between Young’s modulus (E), Bulk modulus (K) and Poisson’s ratio (μ) is given by a. E=2K(1-2μ) b. E=3K(1-2μ) c. E=2K(1-2μ) d. E=2K(1-3μ)

Description : The relationship between Young’s modulus (E), Bulk modulus (K) and Poisson’s ratio (μ) is given by a. E=2K(1-2μ) b. E=3K(1-2μ) c. E=2K(1-2μ) d. E=2K(1-3μ)

Last Answer : b. E=3K(1-2μ)

An animal drawn seed drill has k number of furrow openers 180mm apart. If the speed of operation is 2.0kmph, the area covered (ha), in 8-11day is given by: A. 1.85/1000k B. 28.8 x 10-2k C. k/6.56 D. 1.762k

Description : An animal drawn seed drill has k number of furrow openers 180mm apart. If the speed of operation is 2.0kmph, the area covered (ha), in 8-11day is given by: A. 1.85/1000k B. 28.8 x 10-2k C. k/6.56 D. 1.762k

Last Answer : B. 28.8 x 10-2k

An animal drawn seed drill has k number of furrow openers 180mm apart. If the speed of the operation is 2.0kmph then the area covered (ha), in 8 hr day is given by: a) 1.85/1000k b) 28.8 * 10-2k c) k/6.456 d) 1.762k

Description : An animal drawn seed drill has k number of furrow openers 180mm apart. If the speed of the operation is 2.0kmph then the area covered (ha), in 8 hr day is given by: a) 1.85/1000k b) 28.8 * 10-2k c) k/6.456 d) 1.762k

Last Answer : b) 28.8 * 10-2k

Maximum heat dissipation occurs from a steel wire (k = 0.5 W/m. k) of 15 mm diameter exposed to air (h = 20W/m2.k), when the insulation thickness is __________ mm. (A) 15 (B) 25 (C) 10 (D) 30

Description : Maximum heat dissipation occurs from a steel wire (k = 0.5 W/m. k) of 15 mm diameter exposed to air (h = 20W/m2.k), when the insulation thickness is __________ mm. (A) 15 (B) 25 (C) 10 (D) 30

Last Answer : (B) 25

Robert is using a barrel to collect rain water for his garden. The circular end has a radius of 1ft. The barrel is 3ft wide. How much water will the barrel hold Using V=3.14r^2h?

Description : Robert is using a barrel to collect rain water for his garden. The circular end has a radius of 1ft. The barrel is 3ft wide. How much water will the barrel hold Using V=3.14r^2h?

Last Answer : Answer: the barrel will hold 9.42 ft³ of water.

For a given ambient air temperature with increase in the thickness of insulation of a hot cylindrical pipe, the rate of heat loss from the surface would (A) Decrease(B) Increase(C) First decrease and then increase(D) First increase and then decrease

Description : For a given ambient air temperature with increase in the thickness of insulation of a hot cylindrical pipe, the rate of heat loss from the surface would (A) Decrease (B) Increase (C) First decrease and then increase (D) First increase and then decrease

Last Answer : (D) First increase and then decrease

Identify the products in the following disproportional reaction and also mention rate determining step. `2H-overset(D)overset(|)(C)=O + overset(@)(O)H

Description : Identify the products in the following disproportional reaction and also mention rate determining step. `2H-overset(D)overset(|)(C)=O + overset(@)(O)H

Last Answer : Identify the products in the following disproportional reaction and also mention rate determining step. `2H-overset ... ")+underset("(Q)")("Alcohol")`

Identify the products in the following disproportional reaction and also mention rate determining step. `2H-overset(D)overset(|)(C)=O + overset(@)(O)H

Description : Identify the products in the following disproportional reaction and also mention rate determining step. `2H-overset(D)overset(|)(C)=O + overset(@)(O)H

Last Answer : Identify the products in the following disproportional reaction and also mention rate determining step. `2H-overset ... ")+underset("(Q)")("Alcohol")`

An isolated load W is acting at a distance a from the left hand support, of a three hinged arch of span 2l and rise h hinged at the crown, the horizontal reaction at the support, is (A) Wa/h (B) Wa/2h(C) 2W/ha(D) 2h/W

Description : An isolated load W is acting at a distance a from the left hand support, of a three hinged arch of  span 2l and rise h hinged at the crown, the horizontal reaction at the support, is  (A) Wa/h  (B) Wa/2h (C) 2W/ha (D) 2h/W

Last Answer : (B) Wa/2h

Total pressure on the vertical face of a retaining wall of height h acts parallel to free surface and from the base at a distance of (A) h/4 (B) h/3 (C) h/2 (D) 2h/3

Description : Total pressure on the vertical face of a retaining wall of height h acts parallel to free surface and from the base at a distance of (A) h/4 (B) h/3 (C) h/2 (D) 2h/3

Last Answer : Answer: Option B

A vertical wall is subjected to a pressure due to one kind of liquid, on one of its sides. The total pressure on the wall acts at a distance __________ from the liquid surface. (A) H/3 (B) H/2 (C) 2H/3 (D) 3H/4

Description : A vertical wall is subjected to a pressure due to one kind of liquid, on one of its sides. The total pressure on the wall acts at a distance __________ from the liquid surface. (A) H/3 (B) H/2 (C) 2H/3 (D) 3H/4

Last Answer : Answer: Option C

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 paraboloid of revolution, whose volume equals half the volume of circumscribing cylinder (C) Velocity profile varies hyperbolically and the shear stress remains constant over the cross-section (D) Average flow occurs at a radial distance of 0.5 r from the centre of the pipe (r = pipe radius)

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

. 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 increasing Reynolds number (C) Point of maximum instability exists at a distance of 2r/3 from the pipe wall (r = pipe radius) (D) Skin friction drag, shear stresses, random orientation of fluid particles and slope of velocity profile at the wall are more

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

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)

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)

For Q 45, Tangent vector for line L2 a.i+4j-k b.2i+4j+k c.i-4j-2k d.i+4j+2k

Description : For Q 45, Tangent vector for line L2 a.i+4j-k b.2i+4j+k c.i-4j-2k d.i+4j+2k

Last Answer : d.i+4j+2k

If 2k + 1, 6, 3& + 1 are in AP, then find the value of k. -Maths 10th

Description : If 2k + 1, 6, 3& + 1 are in AP, then find the value of k. -Maths 10th

Last Answer : For an AP a, b, c; 2b = a + c ⇒ (2k + 1) + (3k + 1) = 2×6 5k+2=12 ⇒ 5k = 10 ⇒ k = 2

If the point (2k – 3, k + 2) lies on the graph of the equation 2x + 3y +15 = 0, find the value of k. -Maths 9th

Description : If the point (2k – 3, k + 2) lies on the graph of the equation 2x + 3y +15 = 0, find the value of k. -Maths 9th

Last Answer : Solution :-

Consider the following statements : 1. a^n + b^n is divisible by a + b if n = 2k + 1, where k is a positive integer. -Maths 9th

Description : Consider the following statements : 1. a^n + b^n is divisible by a + b if n = 2k + 1, where k is a positive integer. -Maths 9th

Last Answer : Statement (1) is correct as for k = 1, n = 2 × 1 + 1 = 3. ∴ a3 + b3 = (a + b) (a2 + b2 – ab) which is divisible by (a + b), statement (2) is also correct as for k = 1, n = 2, ∴ a2 – b2 = (a – b) (a + b) which is divisible by (a – b).

If the three points (k, 2k), (2k, 3k) and (3, 1) are collinear then k is equal to -Maths 9th

Description : If the three points (k, 2k), (2k, 3k) and (3, 1) are collinear then k is equal to -Maths 9th

Last Answer : (d) 3Let (x, y) be the co-ordinates of the third vertex of the triangle. Then\(rac{0+2+x}{3}\) = 1 and \(rac{0+0+y}{3}\) = 1⇒ 2 + \(x\) = 3 and y = 3 ⇒ \(x\) = 1, y = 3. ∴ Co-ordinates of vertices of the triangle ... - y3) + x2 (y2 - y3) + x3(y1 - y2)]= \(rac{1}{2}\) [0+6+0] = \(rac{6}{2}\) = 3.

Find the angle between the vectors A = i + 2j - k and  B = -i + j - 2k.

Description : Find the angle between the vectors A = i + 2j - k and  B = -i + j - 2k.

Last Answer : Find the angle between the vectors A = i + 2j - k and B = -i + j - 2k.

If vectors P = 2i + 3j - k and Q = 2i - 5j + 2k. Find i. P + Q ii. 3P - 2Q

Description : If vectors P = 2i + 3j - k and Q = 2i - 5j + 2k. Find i. P + Q ii. 3P - 2Q

Last Answer : If vectors \(\overset\rightarrow{P}\) = 2i + 3j - k and \(\overset\rightarrow{Q}\) = 2i - ... \overset\rightarrow{P}\) - 2\(\overset\rightarrow{Q}\)

Find unit vector parallel to the resultant of the vectors A = i + 4j - 2k and B = 3i - 5j + k.

Description : Find unit vector parallel to the resultant of the vectors A = i + 4j - 2k and B = 3i - 5j + k.

Last Answer : Find unit vector parallel to the resultant of the vectors \(\overset\rightarrow{A}\) = i + 4j - 2k and \(\overset\rightarrow{B}\) = 3i - 5j + k.

If two springs having individual stiffness K, are in parallel, then their equivalent stiffness will be A. 2K B. K C. K/2 D. 4K

Description : If two springs having individual stiffness K, are in parallel, then their equivalent stiffness will be A. 2K B. K C. K/2 D. 4K

Last Answer : A. 2K

The combined mass of car and passengers travelling at 72 km/hr is 1500 kg. Find the kinetic energy of this combined mass. (Formula: K =mv2 / 2k )  a. 300 kJ  b. 200 kJ  c. 500 kJ  d. None of the above

Description : The combined mass of car and passengers travelling at 72 km/hr is 1500 kg. Find the kinetic energy of this combined mass. (Formula: K =mv2 / 2k )  a. 300 kJ  b. 200 kJ  c. 500 kJ  d. None of the above

Last Answer : 300 kJ

For a program of k variables, boundary value analysis yields .............. test cases. (A) 4k – 1 (B) 4k (C) 4k + 1 (D) 2k – 1

Description : For a program of k variables, boundary value analysis yields .............. test cases. (A) 4k – 1 (B) 4k (C) 4k + 1 (D) 2k – 1

Last Answer : (C) 4k + 1

An isothermal aqueous phase reversible reaction, P ⇌ R, is to be carried out in a mixed flow reactor. The reaction rate in k.mole/m3 .h is given by, r = 0.5CP - 0.125CR. A stream containing only P enters the reactor. The residence time required (in hours) for 40% conversion of P is (A) 0.80 (B) 1.33 (C) 1.60 (D) 2.67

Description : An isothermal aqueous phase reversible reaction, P ⇌ R, is to be carried out in a mixed flow reactor. The reaction rate in k.mole/m3 .h is given by, r = 0.5CP - 0.125CR. A stream containing only P enters the reactor. The ... (in hours) for 40% conversion of P is (A) 0.80 (B) 1.33 (C) 1.60 (D) 2.67

Last Answer : (C) 1.60

Frame the formula for the volume (v) of a cylinder given by the product of `pi`, square of radius (r) and height (h).

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).

The radius of Gyration (k) for Rim Type Flywheel having radius ‘r’ is given by 1. k = 2r 2. k = r/2 3. k = r 4. k = r/3

Description : The radius of Gyration (k) for Rim Type Flywheel having radius ‘r’ is given by 1. k = 2r 2. k = r/2 3. k = r 4. k = r/3

Last Answer : 3. k = r

For the given reaction , `A(g) rarr 2B(g) , Delta_(r)H= 30 kJ//"mole" Delta_(r)S = 150 J//mol` at `300 K` If `C_(P,A) = 20 J//K mol` and `C_(P,B) = 20

Description : For the given reaction , `A(g) rarr 2B(g) , Delta_(r)H= 30 kJ//"mole" Delta_(r)S = 150 J//mol` at `300 K` If `C_(P,A) = 20 J//K mol` and `C_(P,B) = 20

Last Answer : For the given reaction , `A(g) rarr 2B(g) , Delta_(r)H= 30 kJ//"mole" Delta_(r)S = 150 J//mol` at ... G` is negative D. At `T = 200, Delta G` is zero

A steam pipe is intended to be insulated with two layers of insulating materials of different thermal conductivities. For minimum heat transfer to take place (A) The better insulation material should be put just next to pipe (i.e., inside) (B) The better insulating material should be put outside (C) Either of the insulating material could be put on either side (D) Steam temperature is considered before deciding as to which insulating material is to be put inside (i.e., just next to the pipe)

Description : A steam pipe is intended to be insulated with two layers of insulating materials of different thermal conductivities. For minimum heat transfer to take place (A) The better insulation material should be put just ... to which insulating material is to be put inside (i.e., just next to the pipe)

Last Answer : (A) The better insulation material should be put just next to pipe (i.e., inside)

Which of the following relations is used to represent theorem of perpendicular axes? (H = Vertical axis, I = Moment of inertia and K = Radius of gyration) a. IPQ = Ixx + AH2 b. IPQ = Ixx + Ak2 c. Izz = Ixx + Iyy d. Izz + Ixx + Iyy = 0

Description : Which of the following relations is used to represent theorem of perpendicular axes? (H = Vertical axis, I = Moment of inertia and K = Radius of gyration) a. IPQ = Ixx + AH2 b. IPQ = Ixx + Ak2 c. Izz = Ixx + Iyy d. Izz + Ixx + Iyy = 0

Last Answer : c. Izz = Ixx + Iyy

Which one is the oxidising agent in the reaction given below `2CrO_(4)^(2-)+2H^(+)rarrCr_(2)O_(7)^(-2)+H_(2)O`

Description : Which one is the oxidising agent in the reaction given below `2CrO_(4)^(2-)+2H^(+)rarrCr_(2)O_(7)^(-2)+H_(2)O`

Last Answer : Which one is the oxidising agent in the reaction given below `2CrO_(4)^(2-)+2H^(+)rarrCr_(2)O_(7)^(-2)+H_(2)O` ... 2)O_(7)^(-2)` C. `Cr^(++)` D. None

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

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.

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.

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`

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,

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)`.