The expected efficiency of a single riveted lap joint is of the order of 50%. If the thickness of the plate is increased four times, then the rivet diameter will have to be increased __________ times.
Two
Four
Six
Eight
Correct Answer :
A. Two
Related Questions
__________ furnace is generally used in the non-ferrous foundries.
Direct arc
Indirect arc
Resistance
Induction
'Cryogenics' is concerned with the generation & use of low temperature in the range of
0°K to 123°K
0°C to - 123°C
0°C to - 273°C
0°K to 273°K
In fluid flow, and heat and mass transfer, one encounters (i) kinematic velocity (μ), (ii) molecular diffusivity (θ) and thermal diffusivity (α). The units of these quantities are.
μ , α and θ all have units of m/s
μ , α and θ all have units of m2/s
α and θ have units of m2/s, while μ has unit of m/s
α and θ have units of m/s, while μ has unit of m2/s
Lead pencil contains
Graphite
Lead sulphide
Lead
Both (B) & (C)
__________ fluid force is not considered in the Navier-Stokes equation.
Turbulent
Viscous
Gravity
Pressure
Which of the following rays has the least wavelength?
Ultraviolet rays
Infrared rays
Cosmic rays
X-rays
A jig is used while __________ a hole.
Boring
Counter boring
Drilling
Enlarging
Cold chisel & hammers are made of
High speed steel
High carbon steel
Forged steel
Mild steel
__________ are normally subjected to sub-zero treatment.
Highly stressed parts
Gauges or precision parts
Cold rolled sheets
Non machinable materials
For which pair of the fuel gases, calorific value (C.V.) of one fuel is almost double that of the other on volume basis (i.e., kcal/Nm3) while the C.V. is same on weight basis (i.e., kcal/kg)?
Propane and acetylene
Propane and LPG
Sewage gas and gobar gas
B.F gas and coke oven gas
__________ property of a material is determined by the Herbert Pendulum device.
Hardness
Tensile
Toughness
Compressive
Co-efficient of performance of a Carnot cycle refrigerator operating between - 23°C and + 27°C is
3
5
0.5
1.5
Steel produced from phosphatic iron is __________ in nature.
Malleable
Ductile
Brittle
Tough
Often earing defects are found during deep drawing operation, because the
Surface finish of the sheet is poor
Sheet material has been given substantial spring back
Starting sheet has planer anisotropy due to its texture
Starting sheet has normal anisotropy due to its texture
An example of unsteady non uniform flow is the flow of liquid under pressure through a
Tapering pipe at constant flow rate
Tapering pipe at either decreasing or increasing flow rate
Long pipeline of constant diameter
None of these
Boiler draught of 10 mm water column is equivalent to
1 kgf/m2
10 kgf/m2
10 kgf/mm2
1 kgf/mm2
Which of the following properties of a solid is not dependent on crystal imperfection?
Ductility
Semi-conductivity
Melting point
Yield stress
When dry bulb temperature & wet bulb temperature of moist air is the same, it means that the
Partial pressure of water vapour is less than the total pressure
Humidity is < 100% & dew point temperature of air has not reached
Dew point temperature of air has not reached & air is not saturated fully
Air is fully saturated
Which of the following represents the correct time-temperature curve when a block of metal is heated above room temperature & then left to cool in the room following Newton's law of cooling in which the rate of temperature drop will go on decreasing with the passage of time.
Which of the following approaches the ideal gas behaviour most closely?
Wet steam
Saturated steam
Superheated steam
Saturated water
Increase in temperature, in general results in the
Decrease in the viscosities of both liquids & gases
Increase in the viscosities of both liquids & gases
Increase in the viscosity of liquids and decrease in that of gases
Decrease in the viscosity of liquids and increase in that of gases
Parallel straight line pattern of temperature distribution for both hot and cold fluids is observed in case of heat exchanger of the type
Parallel flow with equal heat capacities
Counter flow with equal heat capacities
Counter flow with unequal heat capacities
Parallel flow with unequal heat capacities
The cooling rate required to freeze 1 ton of water at 0°C into ice at 0°C in 24 hours is __________ BTU/hr.
100
200
1000
2000
The usual energy consumption in electric arc furnace steel making is __________ KWh/ton of steel.
60 - 100
400 - 700
1200 -1500
2000 - 2300
With increase in __________ Knocking tendency in a spark ignition petrol engine decreases.
Supercharging
Wall temperature
Compression ratio
Engine speed
Holes for riveting purposes should be preferably made by
Cutting torch
Drilling
Punching
None of these
Which of the following is an acidic constituent of B.F. slag?
FeO
MgO
CaO
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.
2
8
10
40
The transition temperature at which all the ferromagnetic materials become paramagnetic materials is termed as the 'Curie temperature'. Its value for cobalt is __________ °C.
768
1127
1359
1480
Which of the following is a boiler accessory
i.e., not a boiler mounting?
Blow off cock
Feed check valve
Feed water pump
Stop valve