An industry consumes 4000 units of a product on annual basis. Delivery lead time is 9 days. The reorder point to achieve optimum inventory (in number of units) will be ________.
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Solution
Given: Number of units = 4000
Delivery lead time = 9 days
Reorder level (point) =\(\frac{4000}{365}\times 9\) = 99 units
The specification of a shaft is provided as 45\(\overset{0.060}{0.000}\)mm.Minimum clearance and tolerance are 0.02 mm and 0.05 mm respectively.The maximum clearance between hole and shaft will be ________.
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Solution
Given: Minimum hole size = 45 + 0.02 = 45.02 mm
Maximum hole size = 45.02 + 0.05 = 45.07 mm
Maximum clearance =45.07 – 45= 0.07 mm
Steel shuts are to welded by spot welding.The following data is provided
Steel sheet thickness =3 mm
Current = 6000 Amp
Time for flow of current = 0.185
Diameter of electrodes=8 mm Resistance=250 μΩ
Density of metal = 8000 kg/m3
Specific energy for melting = 1.8 MJ/kg
Based on the above data,the heat generated will be________.
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Solution
Heat generated in weld (Qg)
Qg=I2Rt
where,I = current,
R = Resistance
t = time,
Given: I = 6000 amp, R = 250 × 10–6 W, t = 0.185
Qg= (6000)2 × 250 × 10–6 × 0.18
= 1620 J
The extrusion process is to be performed on a work-piece to extrude the diameter from 130 mm to 85 mm. The temperature during operation and extrusion constant are 900°C and 400MPa respectively. Then the force required will be ________.
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Solution
Addition of Vanaum to steel results in improvement of:
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Solution
Hardenability increases, when vanadium is added to steel.
A straight bar is fixed at A and B as shown in figure. A load P= 120 N is acting at point c. Then the reactions at the end will be ________.
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Solution
The velocity ratio between pinion and gear in a gear drive is 2.3, the module of teeth is 2 mm and sum of number of teeth on pinion and gear is 99. Then the centre distance between pinion and gear will be _______.
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Solution
Water (CP= 4kJ/kgk) is fed to a boiler at 30°C, the enthalpy of vaporization at atmospheric pressure in the boiler is 24000kJ/kg, the steam coming from the boilder is 0.9 dry.The net heat supplied in the boiler will be _________.
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Solution
Given: Specific heat (CP) = 4 kJ/KgK
Enthalpy (DH) = 2400 kJ/kg
Temperature = 30°C
dry steam (DS) =0.9
Net heat supplied in boiler=Q +ΔH
= CpdT + ΔH × DS
= 4(100 – 30) + 2400 × 0.9
= 4 × 70 + 2160
= 2440 kJ/Kg
The order of values of thermal efficiency of otto, diesel and dual cycler, when they have equal compression ratios and heat rejection, is given by
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Solution
In otto cycle, thermal efficiency is highest and in diesel cycle, thermal efficiency is minimum. While thermal efficiency of dual cycle lie in between the above two.As Heat rejection for otto cycle is minimum and for diesel cycle,if is maximum. So,
ηotto > ηdual > ηdiesel
The cavitation number of any fluid machinery is defined \(\sigma =\frac{P-P’}{\rho v^{2}/2}\) where,P = absolute pressure, p = density v =free stream velocity, then the symbol p’ denotes:
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Solution
In the formula
Cavitation number (σ) =\(\frac{P-P'}{PV^{2/2}}\)
P' → Vapour pressure of fluid