Engineering Answers

Consider a dc machine whose circuit model is drawn below. It is a separately excited

machine as its field coil (winding) is excited from a voltage source independent of the

armature circuit. A 25 kW, 250 V dc machine is separately excited. The field current

is held constant at a speed of 3000 rpm. The open circuit voltage is 250 V. Calculate

the terminal power, electromagnetic power and torque at terminal voltage of 255 V

and 248 V. The armature resistance is 0.05 W. Speed is held constant at 3000 rpm.

Draw the isometric view of a regular cylinder of diameter 80 and height 70

A digital computer has a common bus system for 4 registers (A, B, C, D) of 8 bits each.

a) Construct the common bus system with multiplexers, showing their inputs and their selection variables (S_o, S₁).

b) Draw the diagram of the bus system, but use three-state buffers and a decoder

Develop the lateral surface of regular hexagonal prism of base edge 35 and height 60.

Draw the isometric view of a regular hexagonal prism of base edge 35 and height 60.

Draw the isometric view of a regular cylinder of diameter 80 and height 70

A 400 kVA transformer has a primary winding resistance of 0.5and a secondary winding resistance of 0.001. The iron loss is 2.5 kW and the primary and secondary voltages are 5 kV and 320V, respectively. If the power factor of the load is 0.85, determine the efficiency of the transformer on full load.

what interest rate compounded monthly is equivalent to an interest rate of 9 compounded quarterly?

The adsorption of pure propane on activated carbon at different temperatures and pressures is given as: T = 311 K T = 338.7 K T = 394 K p q p q p q 2.266 1.044 6 1.069 7.067 0.7099 15.6 2.819 27.2 2.469 38.67 1.677 31.74 3.48 53.2 3.078 83.21 2.238 59.6 3.968 92.67 3.512 98.54 2.37 89.74 4.207 99.97 3.635 99.97 2.4 99.97 4.342 244.8 4.188 303.4 3.251 293 4.94 424 4.475 482.6 3.599 Where, p = partial pressure of propane (kPa); q = amount of propane adsorbed at equilibrium (mmol/g carbon). a. Draw the adsorption isotherms at the above 3 temperatures. (03) b. Determine the isosteric heat of adsorption at constant solute loading of 3.0 and 3.5 mmol/g carbon, respectively.

A drier takes 7 h to dry a wet material from 33% moisture content to 9%. The critical and equilibrium moisture content were 16% and 5%. Determine the time needed to dry a similar material from 37% to 7% under similar drying conditions. All the percentages given above are on dry basis.