Alternating current

What is alternating current

• the process of inducing an emf (voltage) with a change in magnetic flux

• Electric currents whose direction and magnitude change periodically depending on time

• Steady current which delivers the same average power as the a.c. to a resistive load.

• Making a rectified current more steady (or smooth) by placing a capacitor in parallel with the resistor​

What does AC smoothing mean?

• the process of inducing an emf (voltage) with a change in magnetic flux

• Electric currents whose direction and magnitude change periodically depending on time are called alternating current

• Steady current which delivers the same average power as the a.c. to a resistive load.

• Making a rectified current more steady (or smooth) by placing a capacitor in parallel with the resistor​

Defines of the effective value of alternating current

• The process of inducing an emf (voltage) with a change in magnetic flux

• Electric currents whose direction and magnitude change periodically depending on time are called alternating current

• Steady current which delivers the same average power as the a.c. to a resistive load.

• Making a rectified current more steady (or smooth) by placing a capacitor in parallel with the resistor​

Electromagnetic Induction is ...

• The process of inducing an emf (voltage) with a change in magnetic flux

• Electric currents whose direction and magnitude change periodically depending on time are called alternating current

• Steady current which delivers the same average power as the a.c. to a resistive load.

• Making a rectified current more steady (or smooth) by placing a capacitor in parallel with the resistor​

If the Y-sensitivity and time-base for the trace shown in Figure are 5 V/cm and 20 ms/cm, what are the amplitude, period and frequency of the signal to Y-input?

• 3.5 V, 80 ms, 50 Hz

• 20 V, 40 ms, 50 Hz

• 17.5 V, 80 ms, 12.5 Hz

• 22.5 V, 12.5 ms, 55 Hz

Find the inductive reactance of the circuit shown in the figure

• 100Ω

• 6,28Ω

• 3,14Ω

• 5,22Ω

A series RLC circuit has a resistance of 10.0 Ω and a impedance of 50.0 Ω. If the rms voltage applied to the circuit is 10 V, what average power?

• 0.4W

• 4W

• 5W

• 50W

A series RLC circuit has a resistance of 10.0 Ω and a impedance of 50.0 Ω. If the rms voltage applied to the circuit is 10 V, what rms current?

• 0.5A

• 1A

• 2A

• 0.2A

What is the phase difference between voltage and current in an alternating current circuit if the inductive reactance is 26 Ohm, the capasitive reactance is 20 Ohm and the active resistance is 8 Ohm?

• 53⁰

• 25⁰

• 120⁰

• 67⁰

What is not the reason for the loss of power in the transformer

• Heat loss due to the resistance of the coils​

• Leakage of magnetic field lines between the primary and secondary coils

• Heat loss due to eddy currents induced in the iron core

• Heat loss due to radiation of electromagnetic waves

• Heat loss due to repeated magnetization and demagnetization of the core