Description : The left face of a one dimensional slab of thickness 0.2 m is maintained at 80°C and the right face is exposed to air at 30°C. The thermal conductivity of the slab is 1.2 W/m.K and the heat transfer co-efficient from the ... temperature of the right face in °C is (A) 77.2 (B) 71.2 (C) 63.8 (D) 48.7
Last Answer : (D) 48.7
Description : A metal wire of 0.01 m dia and thermal conductivity 200 W/m.K is exposed to a fluid stream with a convective heat transfer coefficient of 100 W/m2 .K. The Biot number is (A) 5.6 (B) 0.025 (C) 3.5 (D) 0.0035
Last Answer : (B) 0.025
Description : A 10 cm dia steam pipe, carrying steam at 180°C, is covered with an insulation (conductivity = 0.6 W/m.°C). It losses heat to the surroundings at 30°C. Assume a heat transfer co-efficient of 0 ... that of the un-insulated steam pipe (D) Less than the steam pipe with 5 cms insulation
Last Answer : (B) Less than that of the un-insulated steam pipe
Description : One face of a furnace wall is at 1030°C and the other face is exposed to room temperature (30°C). If the thermal conductivity of furnace wall is 3 W. m-1. k-1 and the wall thickness is 0.3 m, the maximum heat loss (in W/m) is (A) 100 (B) 900 (C) 9000 (D) 10000
Last Answer : (D) 10000
Description : The heat flux (from outside to inside) across an insulating wall with thermal conductivity, K = 0.04 W/m.°K and thickness 0.16m is 10 W/m2 . The temperature of the inside wall is - 5°C. The outside wall temperature is (A) 25°C (B) 30°C (C) 35°C (D) 40°C
Last Answer : (C) 35°C
Description : A thin, flat & square plate measuring 2 m 2 m is freely hanging in ambient air at 25°C. It is exposed to the solar radiation falling on one side of the plate at the rate of 500 W/m2. The plate temperature will ... heat transfer co-efficient is __________ W/m2 °C. (A) 50 (B) 100 (C) 150 (D) 200
Last Answer : (B) 100
Description : The difference in the reservoir level and the lowest point of the water mains is 180 m. The expected pressure due to water hammer is 7.5 kg/cm2 in a pressure conduit of diameter 1 m. Assuming the efficiency of the ... , is (A) 10 mm (B) 15 mm (C) 20 mm (D) 25 mm
Last Answer : (C) 20 mm
Description : A furnace is made of a refractory brick wall of thickness 0.5 metre and thermal conductivity 0.7 W/m.°K For the same temperature drop and heat loss, this refractory wall can be replaced by a layer of diatomaceous earth of ... and thickness __________ metre. (A) 0.01 (B) 0.1 (C) 0.25 (D) 0.5
Last Answer : (B) 0.1
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
Description : The frame consists of a steel beam welded rigidly to two vertical channels. An eccentric exciter weighing 250 N is attached to the beam, which weighs 10 KN and is used to excite the frame. The unbalance weight of ... ends, magnification factor at resonance is A. 307.5 B. 3.075 C. 30.75 D. 0.3075
Last Answer : C. 30.75
Description : Mean drift velocity of electron in a copper wire having cross-sectional area 5.0 × 10-6 m2 carrying current of 1 A and having number density 8.5 × 1028 m3 is A. 0.015 mm s-1 B. 0.1 mm s-1 C. 0.5 mm s-1 D. 0.25 mm s-1
Last Answer : 0.015 mm s-1
Description : The maximum thickness of the metal which can be welded using ultrasonic welding is __________ mm. (A) 0.5 (B) 3 (C) 10 (D) 25
Last Answer : (B) 3
Description : The minimum thickness of the cover at the end of a reinforcing bar should not be less than twice the diameter of the bar subject to a minimum of (A) 10 mm (B) 15 mm (C) 20 mm (D) 25 mm
Last Answer : Answer: Option D
Description : Coating thickness in case of galvanising of steel sheet generally corresponds to the deposition of __________ gms of zinc per m2 of steel strip. (A) 5-10 (B) 1000-1500 (C) 120-500 (D) 1500-3000
Last Answer : Option C
Description : A wire of mild steel has initial length 1.5 m and diameter 0.60 mm is extended by 6.3 mm
Last Answer : A wire of mild steel has initial length 1.5 m and diameter 0.60 mm is extended by 6.3 mm when a ... is 2.1 1011 N/m2, calculate the force applied.
Description : Unnecessary and frequent applications of varnish to the generator windings to repair defective insulation will result in ____________. A. heavy coatings of varnish interfering with heat dissipation B. ... of the rectifier assembly D. a built-up of varnish without changing generator operation
Last Answer : Answer: A
Description : For determining the ultimate bearing capacity of soil, the recommended size of a square bearing plate to be used in load plate test should be 30 to 75 cm square with a minimum thickness of (A) 5 mm (B) 10 mm (C) 15 mm (D) 25 mm
Description : A helical spring is fabricated by wrapping wire 19.05 mm in diameter around a forming cylinder 203.2 mm in diameter. Compute the number of turns required to permit an elongation of 101.6 mm. without exceeding a shearing ... G = 82737 N/mm2. a. 10 turns b. 20 turns c. 25 turns d. 30 turns
Last Answer : a. 10 turns
Description : If a cable of homogeneous insulation has a maximum stress of 10 kV/mm, then the dielectric strength of insulation should be (a) 5 kV/mm (b) 10 kV/mm (a) 15 kV/mm (d) 30 kV/mm
Last Answer : (b) 10 kV/mm
Description : The resistance of a conductivity wire of length 1.1 m and of diameter 0.14 mm is `30 Omega`. Calculate its resistivity.
Last Answer : The resistance of a conductivity wire of length 1.1 m and of diameter 0.14 mm is `30 Omega`. Calculate its resistivity.
Description : Determine the maximum shearing stress and elongation in a helical steel spring composed of 20 turns of 20-mm-diameter wire on a mean radius of 90 mm when the spring is supporting a load of 1.5 kN. and G = 83 GPa. a. 200 mm b. 105.4 mm c. 150 mm d. 250 mm
Last Answer : b. 105.4 mm
Description : Pick out the wrong statement. (A) For a pressure vessel to be classified as 'thin vessel', the ratio of wall thickness to mean radius is less than 0.1 (B) For calculating forces and ... Maximum diameter of the opening provided in a pressure vessel, which does not require any compensation is 200 mm
Last Answer : Option B
Description : A rheostat has 100 turns of a wire of radius 0.4 mm having resistivity `4.2xx10^(-7) Omega`m. The diameter of each turn is 3 cm. What is the maximum v
Last Answer : A rheostat has 100 turns of a wire of radius 0.4 mm having resistivity `4.2xx10^(-7) ... the maximum value of resistance that it can introduce ?
Description : The interfacial area per unit volume of dispersion, in a gas-liquid contactor, for fractional hold up of gas = 0.1 and gas bubble diameter = 0.5 mm is given by (in m2 /m3 ) (A) 500 (B) 1200 (C) 900 (D) 800
Last Answer : (A) 500
Description : A load of 1960 N is raised at the end of a steel wire. The minimum diameter of the wire so that stress in the wire does not exceed 100 N/mm2 is: (A) 4.0 mm (B) 4.5 mm (C) 5.0 mm (D) 5.5 mm
Last Answer : (C) 5.0 mm
Description : A practical formula for determining the thickness of insulation between low voltage and high voltage windings is (a) 1 + 0.2 kVmm (6) 2 + 0.5 kVmm (c) 4 + 0.7 kV mm (d) 5 + 0.9 kV mm
Last Answer : (d) 5 + 0.9 kV mm
Description : A spring of mean radius 40 mm contains 8 action coils of steel (N = 80000 N/mm2 ), 4 mm in diameter. The clearance between the coils being 1 mm when unloaded, the minimum compressive load to remove the clearance, is (A) 25 N (B) 30 N (C) 35 N (D) 40 N
Last Answer : (C) 35 N
Description : In slump test, each layer of concrete is compacted by a steel rod 60 cm long and of 16 mm diameter for (A) 20 times (B) 25 times (C) 30 times (D) 50 time
Last Answer : Answer: Option B
Description : Minimum cover to longitudinal steel in a column should be (if the diameter of bar, Ø> 12mm) [ A ] 25 mm [ B ] 30 mm [ C ] 40 mm [ D ] 50 mm
Last Answer : [ C ] 40 mm
Description : What length of a wire of diameter 0.46 mm and specific resistance `50xx10^(-6) Omega`m would be required to make a coil of resistance `10 Omega` ?
Last Answer : What length of a wire of diameter 0.46 mm and specific resistance `50xx10^(-6) Omega`m would be required to make a coil of resistance `10 Omega` ?
Description : The minimum cover in a slab should neither be less than the diameter of bar nor less than (A) 10 mm (B) 15 mm (C) 25 mm (D) 13 mm
Description : Minimum clear cover (in mm) to the main steel bars in slab, beam, column and footing respectively, are (a) 10, 15, 20 and 25 (b) 15, 25, 40 and 75 (c ) 20, 25, 30 and 40 (d) 20, 35, 40 and 75
Last Answer : (b) 15, 25, 40 and 75
Description : For a clay slope of height of 10 m, the stability number is 0.05, = 2.0 t/m3 , C = 2.5 t/m2 , the critical height of the slope of the soil, is (A) 4.0 m (B) 12.5 m (C) 25.0 m (D) 15.0 m
Last Answer : (C) 25.0 m
Description : What is the characteristic impedance of a single wire with a diameter d= 0.25 mm placed at the center between grounded parallel planes separated by 1 mm apart. The wire is held by a material with a velocity factor of 0.75. A. 85 Ω B. 63 Ω C. 50 Ω D. 75 Ω
Last Answer : D. 75 Ω
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
Description : A hollow shaft of 1 m length is designed to transmit a power of 30 kW at 700 rpm. The maximum permissible angle of twist in the shaft is 1o. The inner diameter of the shaft is 0.7 times the outer diameter. The modulus of ... shaft is _______. (a) 43 to 45 (b) 50to 60 (c) 70 to 80 (d) 85 to 100
Last Answer : (a) 43 to 45
Description : For a longitudinal reinforcing bar in a column, the minimum cover shall neither be less than the diameter of bar nor less than (A) 15 mm (B) 25 mm (C) 30 mm (D) 40 mm
Description : The temperature coefficient of copper is `0.004^(@)C^(-1)`. Find the resistance of a 5 m long copper wire of diameter 0.2 mm at `100^(@)C`, if the res
Last Answer : The temperature coefficient of copper is `0.004^(@)C^(-1)`. Find the resistance of a 5 m long copper wire of ... `0^(@)C` is `1.7xx10^(-8) Omega` m.
Description : If the width of a pavement slab is 7.5 m, thickness 20 cm and working stress 1400 kg/cm2 , spacing of 10 mm tie bars for the longitudinal joint, is (A) 10 cm (B) 20 cm (C) 30 cm (D) 40 cm
Last Answer : Answer: Option C
Description : In finish machining of an island on a casting with CNC milling machine, an end mill with 10 mm diameter is employed. The corner points of the island are represented by (0, 0), (0, 30), (50, 30) and (50, 0). By applying cutter radius right ... , 5), (5, 5) d.(5, 5), (45, 5), (45, 25), (5, 25), (5, 5)
Last Answer : a.(-5, 0), (-5, 35), (55, 35), (55,-5), (-5,-5)
Description : The maximum thickness of expansion joint in rigid pavements is (A) 0 (B) 25 mm (C) 50 mm (D) 100 mm
Description : Potential flow is characterised by the (A) Irrotational and frictionless flow (B) Irrotational and frictional flow (C) One in which dissipation of mechanical energy into heat occurs (D) Formation of eddies within the stream
Last Answer : (A) Irrotational and frictionless flow
Description : The overall heat transfer co-efficient for a shell and tube heat exchangerfor clean surfaces is U0 = 400 W/m2 .K. The fouling factor after one year of operation is found to be hd0 = 2000 W/m2 .K. The overall heat transfer coefficient ... 1200 W/m2 .K (B) 894 W/m2 .K (C) 333 W/m2 .K (D) 287 W/m2 .K
Last Answer : (C) 333 W/m2 .K
Description : The thermal radiative flux from a surface of emissivity = 0.4 is 22.68 kW/m2 . The approximate surface temperature (K) is (Stefan-Boltzmann constant = 5.67 × 10 -8 W/m2 .K4 ) (A) 1000 (B) 727 (C) 800 (D) 1200
Last Answer : (A) 1000
Description : A standard steel tape of length 30 m and cross-section 15 1.0 mm was standardised at 25°C and at 30 kg pull. While measuring a base line at the same temperature, the pull applied was 40 kg. If the modulus of elasticity of ... (A) - 0.000909 m (B) + 0.0909 m (C) 0.000909 m (D) None of these
Last Answer : (A) - 0.000909 m
Description : 200 kg of solids (on dry basis) is subjected to a drying process for a period of 5000 seconds. The drying occurs in the constant rate period with the drying rate as, Nc = 0.5 10 -3 kg/m2 .s. The initial ... moisture/kg dry solid). (A) 0.5 (B) 0.05 (C) 0.1 (D) 0.15
Last Answer : (C) 0.1
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 : A simply supported beam carries uniformly distributed load of 20 kN/m over the length of 5 m. If flexural rigidity is 30000 kN.m2, what is the maximum deflection in the beam? a. 5.4 mm b. 1.08 mm c. 6.2 mm d. 8.6 mm
Last Answer : a. 5.4 mm
Description : What is the resistance of a 160 m wire with a uniform diameter of 0.28 mm, if the specific resistance is 12.32 μΩ-cm? A) 3.2 Ω B) 3.2 μΩ C) 0.8 Ω D) None of these
Last Answer : What is the resistance of a 160 m wire with a uniform diameter of 0.28 mm, if the specific resistance is 12.32 μΩ-cm? A) 3.2 Ω B) 3.2 μΩ C) 0.8 Ω D) None of these
Description : A cylinder is said to be thin if the ratio of its thickness and diameter, is less than (A) 1/25 (B) 1/20 (C) 1/15 (D) 1/10
Last Answer : (D) 1/10