(EL2-1) Diode Characteristics

An ideal diode should have

1 Zero resistance in the forward bias as well as reverse bias.
2 Zero resistance in the forward bias and an infinitely large resistance in reverse bias.
3 Infinitely large resistance in reverse bias.
4 Infinitely large resistance in forward as well as reverse bias.

An ideal diode is one which behaves as a perfect _______ when forward biased.:

1 Insulator
2 Conductor
3 Semiconductor
4 None of the above.

The d.c. resistance of a diode is___ Its a.c. resistance.

1 Greater than
2 Less than
3 More than
4 None of the above.

What is the state of an ideal diode in the region of non conduction?

1 An open circuit.
2 A short circuit.
3 Unpredictable.
4 Undefined.

The diode _____.

1 is the simplest of semiconductor devices
2 has characteristics that closely match those of a simple switch.
3 is a two-terminal device
4 All of the above

What does a high resistance reading in both forward- and reverse-bias directions indicate?

1 A good diode
2 An open diode
3 A shorted diode
4 A defective ohmmeter

What is the state of an ideal diode in the region of non conduction?

1 An open circuit
2 A short circuit
3 Unpredictable
4 Undefined

At what kind of operating frequency diffusion or transition is a capacitor represented in parallel with the ideal diode?

1 Low frequency
2 Moderate frequency
3 Mid frequency
4 Very high frequency

Calculate static resistance RD of a diode having ID = 30 mA and VD = 0.75 V.

1 25 ohm
2 40 ohm
3 250 ohm
4 400 ohm

Calculate ID if RD = 30 ohm and VD = 0.84 V.

1 280 ??A
2 0.028 mA
3 28 mA
4 2.8 A

When matching polarity connections have been made and the potential difference (PD) is above 0.7 V, the diode is considered to be:

1 Not working
2 Forward biased
3 Reverse biased
4 An open switch

The characteristic curve for the complex model of a silicon diode shows that

1 the barrier potential is 0 V
2 the barrier potential stays fixed at 0.7 V
3 the barrier potential increases slightly with an increase in current
4 the barrier potential decreases slightly with an increase in current

Testing a good diode with an ohmmeter should indicate

1 high resistance when forward or reverse biased
2 low resistance when forward or reverse biased
3 high resistance when reverse biased and low resistance when forward biased
4 high resistance when forward biased and low resistance when reverse biased

When a diode is forward biased, the voltage across it

1 is directly proportional to the current
2 is directly proportional to the current
3 is directly proportional to the source voltage
4 remains approximately the same

The arrow in the schematic symbol of a diode points to

1 the n-type material, which is called the anode
2 the n-type material, which is called the cathode
3 the p-type material, which is called the anode
4 the p-type material, which is called the cathode

The diode schematic arrow points to the:

1 trivalent-doped material
2 positive axial lead
3 anode lead
4 cathode lead

When checking a diode, low resistance readings both ways indicate the diode is:

1 Open
2 Satisfactory
3 Faulty
4 not the problem

When a diode is destroyed it has infinite impedance. When damaged by heat it will probably:

1 Short
2 conduct more
3 conduct less
4 open

DC power should be connected to forward bias a diode as follows:

1 ??? anode, + cathode
2 ??? cathode, ??? anode
3 + anode, ??? cathode
4 + cathode, + anode


V = volt