0 of 17 Questions completed
Questions:
You have already completed the quiz before. Hence you can not start it again.
Quiz is loading…
You must sign in or sign up to start the quiz.
You must first complete the following:
0 of 17 Questions answered correctly
Your time:
Time has elapsed
You have reached 0 of 0 point(s), (0)
Earned Point(s): 0 of 0, (0)
0 Essay(s) Pending (Possible Point(s): 0)
Q1 – A conductor 25cm long moves through a magnetic field at a velocity of 10m/s.
Calculate the value of the induced emf in the conductor when it is at an angle of 80° to the plane of the magnetic field and the flux density of the field is 0.412 tesla.
This response will be reviewed and graded after submission.
Q2 – Define dynamically induced emf
This response will be reviewed and graded after submission.
Q3 – The current equation for a circuit is i = 200 sin 628/. What are the values of the following?
a) The RMS current
b) The frequency
c) 190,2 A
This response will be reviewed and graded after submission.
Q4 – When is maximum emf induced in a coil rotating at a constant speed in a uniform magnetic field?
This response will be reviewed and graded after submission.
Q5 – How can the angular velocity of an alternating emf be determined?
This response will be reviewed and graded after submission.
Q6 – Define the following terms of AC waves: instantaneous value, RMS value and form factor
This response will be reviewed and graded after submission.
Q7 – A conductor 100 mm long rotates through a magnetic field at a velocity of 45 mls. The flow density of the field is 0,12 tesla.
Calculate:
a) The value of the maximum induced emf in the conductor
b) The instantaneous emf at an angle of 40° to the plane of the magnetic field
This response will be reviewed and graded after submission.
Q8 – Explain the term self-induction
This response will be reviewed and graded after submission.
Q9 – Define statically induced emf.
This response will be reviewed and graded after submission.
Q10 – Define the term power-factor.
This response will be reviewed and graded after submission.
Q11 – Explain the meaning of the term impedance with regard to an AC circuit.
This response will be reviewed and graded after submission.
Q12 – Name TWO methods applied in practice to improve a poor power factor.
This response will be reviewed and graded after submission.
Q13 – A series circuit consists of a resistor of 40 ohms, a capacitor with a capacitive reactance of 60 ohms and an inductance with an inductive reactance of 40 ohms. If the supply voltage is 220V at a frequency of 50 Hz
Calculate:
a) The impedance of the circuit
b) The current flowing
c) The power factor
d) The inductance of the circuit
This response will be reviewed and graded after submission.
Q14 – A single-phase circuit consumes 4,2 KW at a power factor of 0,6 lagging. Find the value of the apparent input power and the reactive power under these conditions.
This response will be reviewed and graded after submission.
Q15 – Make two stretches to illustrate star and delta connections. Indicate the line, and phase voltages and currents on the diagrams.
Upload your answer to this question.
This response will be reviewed and graded after submission.
Q16 – A 10 KW, Three -phase, 380-V motor is started by means of a star-delta starter. What is the phase voltage when the starter is:
a) In the star position?
b) In the delta position?
This response will be reviewed and graded after submission.
Q17 – A three-phase delta-connected motor draws a current of 8 A from a 525-V supply at a power factor of 0,9 lagging.
Determine:
a) The apparent input power
b) The actual input power
c) The phase currents of the motor’s windings
This response will be reviewed and graded after submission.