Engineering Answers

A flat belt is required to transmit 22 kW from a 250 mm diameter pulley running at 1450 rpm to a 355 mm diameter pulley. The proposed belt is 3.5 mm thick. The other system specifications are as follows: Coefficient of friction 0.7, Density of the belt is 1100 kg/m3, Maximum permissible stress is 7 MPa. The distance between the shafts is 1.8 m.

Calculate the width required. 

A 20° full depth spur pinion is required to transmit 1.8 kW at a speed of 1540 rpm. If the pinion has 21 teeth and is manufactured from a heavy duty 817M40 steel; Select a suitable gear from the limited choice given in Tables 6.7 -6.10, specify the:

1.1 module and face width based on the Lewis formula. (9)

1.2 the gear module and the face width if the power transmitted is doubled (3)

1.3 the gear module and the face width if the speed is doubled and the power is still 1.8 kW? (3)

Hint: In all the above, show all your calculation steps (Start with m =1) in all cases.

Derive the VDS equation as a function of VGS, for the following MOSFET based amplifier. Please use current equations of MOSFET, as discussed in the class. As per class discussion, we know this circuit can be used as an AC amplifier. Please discuss how can the gain of this AC amplifier, be enhanced

Example 2: To move charge q from point a to point b requires -30J. Find the voltage drop vh if: (a) q = 6 C, (b) q - -3 C.

26. Which one is a better choice, a large diameter piles or a system of several smaller piles with the same load capacity?

24. For a rigid pile cap with vertical piles at the middle and raking piles at the sides, what is the pattern of load distribution of piles in such arrangement?

25. What are the problems associated with prestressed concrete piles (Daido)?