A photomultiplier tube (PMT) contains a photoemissive cathode that emits a single electron when struck by a photon. The electron is accelerated through a series of dynodes before being collected at the anode. If each dynode emits, on average, 5.5 electrons for each incident electron, calculate the overall gain of the PMT if it contains 8 dynodes (the cathode, 8 dynodes and the final anode).

Aloaded platform of total mass 500 kg is supported by a dashpot and by a set of springs of effective stiffness 72 kn/m. it is observed that when the platform is depressed through a distance x = 12.5 cm below its equilibrium position and then released without any initial velocity; it reaches its equilibrium position in the shortest possible time without overshoot. find the position and velocity of the loaded platform 0.10 sec. after its release. if a further load of 400 kg is added to the platform, find, i) the frequency of damped vibrations, and i) the amplitude of vibration after 2 complete oscillations, given that the initial amplitude is 15 cm.

Acompressor receives the shaft work to decrease the pressure of the fluid. a)- true b)- false

Manometers are good examples of measuring instruments, nowadays they are not as common as before. a)-capacitive probe gauges b)-gravitational gauges deformation ) gauges d)-digital gauges