Electrical Engineering Answers

if a force of 6900N is raised in a height of 15meters in 36 seconds what is the work done and the power developed?

an energy source forces a constant current of 2.5amps for 20 seconds to flow through a light bulb. if 3kilojoules is given of in the form of light and heat energy calculate the charge of the current and the voltage drop across the bulb.

Determine the frequency of sound heard by a stationary listener when a moving siren emits 550Hz and travels away at 50m/s from the listener assuming the air temperature is 20 degree Celsius.

1. Two heating units A and B are connected in parallel across 120 volts supply. Unit B takes twice as much power as A and the total power is 2160 watts. Determine the resistance of A and B in ohms. 

How many sheets of a dielectric are necessary to make a condenser having a capacity of 5.5nF when the sheets are 15cm x 30cm in area and 0.29cm thick? Use k = 8

5. An 18mm diameter rivet is used to fasten two 22mm thick plate. If the

shearing stress is 60 MPA. What tensile force applied each plate to shear the

bolt?

( Ans F=15.27KN )

2. If the ultimate shear strength of a steel plate is 35000psi, what force is

necessary to punch a 0.35 in. diameter hole in a 0.255 in. thick plate?

( Ans F=9813.55 lb )

The primary winding of an electric train transformer has 400 turns and the secondary has 50. If the input voltage is 120V(rms) what is the output voltage?

Dimension of susceptibility is

1/ Coulomb

Coulomb^2

It is dimensionless

None of the above

To measure the voltage across a particular resistor, a voltmeter must be connected in series with the resistor.