AMIE Study Circle Blog

Boiler Mechanics Problem (Jharkhand BOE 2024) A solid round bar 3 m long 5cm in diameter is used as a strut with both ends hinged. Determine the crippling load. Take E=2 x 10 5 N/mm 2 . (Jharkhand BOE 2024) Solution Moment of inertia \(I = \frac{\pi }{{64}}x{5^4} = 30.68\,c{m^4} = 30.68x{10^4}\,m{m^4}\)                         Both ends of the bar are hinged. Crippling load for this condition is \(P = \frac{{{\pi ^2}EI}}{{{l^2}}} = \frac{{{\pi ^2}x2x{{10}^5}x30.68x{{10}^4}}}{{{{3000}^2}}}\)                           = 67288 N = 67.288 kN Problem (Jharkhand BOE 2022, 3 marks) A hollow shaft is to transmit 300 kW at 80rpm. If shear stress is not to exceed 60 N/mm 2 a diameter is 0.6 of the external diameter, find external and internal diameters maximum torque is 1.4 times the mean torque. (Jharkhand BOE 2022, 3 marks) Solution   ...

An Air Sample taken from old waterlogged workings showed the following composition. CO 2 -3.0 percent, O 2 - 16.2 percent, N 2 - 79.5 percent, CH 4 - 1.3 percent. (The composition of normal air by volume is O 2 - 20.93 percent, N 2 - 79.04 percent & CO 2 - 0.03 percent). Find the Black damp content of the sample. (DGMS FCMC 2021)

135 ton of coal is to be hauled by direct rope haulage in a shift of 6 hours hauling time where the length of haul is 1100 m. The average speed of rope is 6 km/hr. Set changing time is 1 min & tub capacity is 1.5 ton. Calculate the number of tubs per set?

A 20 m chain was found to be 10 cm too long after chaining a distance of 2000 m. It was found to be 18 cm too long at the end of the day’s work after chaining a total distance of 4000 m. What is the true distance if the chain was correct before the commencement of the day’s work?

Number System

Measurements Fundamentals (Errors and Standards)

Design the 5 sections of a 6-stud starter for a 3-phase slip-ring induction motor The full-load slip is 2% and the maximum starting current is limited to twice the full-load current. Rotor resistance per phase is 0.03 Ω. (AMIE Winter 2023)