Question 1

Which of the following best describes the current-voltage (I-V) characteristic of a semiconductor diode as shown in the provided images?

Accepted Answer

A curve that shows negligible current for negative voltages and a sharp increase in current for positive voltages above a threshold.

Question 2

In the context of the Physics Factsheet on 'Interpreting and Using V-I Graphs', what does the gradient of a V-I graph represent for an ohmic conductor?

Accepted Answer

The resistance of the conductor.

Question 3

Which material is most likely to exhibit the V-I characteristic shown in the second-to-last image (a curve with a sharp increase in current for positive voltage and negligible current for negative voltage)?

Accepted Answer

A semiconductor diode.

Question 4

According to the Physics Factsheet on 'Electrons as Charge Carriers', what happens to the conductivity of a semiconductor as temperature increases?

Accepted Answer

It increases because more electrons are promoted to the conduction band.

Question 5

Which of the following best describes the effect of impurities (doping) in a semiconductor, as discussed in the Physics Factsheet?

Accepted Answer

Impurities increase the number of free charge carriers, enhancing conductivity.

Question 6

In the context of the Physics Factsheet, what is the main difference between the conduction electrons in a metal and those in a semiconductor?

Accepted Answer

Metals have a much higher density of free electrons compared to semiconductors.

Question 7

Which graph best represents the V-I characteristic of a filament lamp, as shown in the Physics Factsheet?

Accepted Answer

A curve that becomes less steep as voltage increases, indicating increasing resistance.

Question 8

What is the effect of increasing the temperature on the resistance of a metallic conductor, according to the Physics Factsheet?

Accepted Answer

Resistance increases as temperature increases.

Question 9

Which of the following statements about the drift velocity of electrons in a conductor is correct?

Accepted Answer

Drift velocity is inversely proportional to the number of free charge carriers per unit volume.

Question 10

In a circuit containing a semiconductor diode, what happens when the diode is reverse biased?

Accepted Answer

The resistance becomes very high and almost no current flows.

Question 11

Which of the following best describes the V-I characteristic of a Zener diode in reverse bias, as shown in the Physics Factsheet?

Accepted Answer

Current increases sharply after a certain reverse voltage (the Zener voltage).

Question 12

According to the Physics Factsheet, what is the effect of increasing the light intensity on the current through a light-dependent resistor (LDR)?

Accepted Answer

The current increases as light intensity increases.

Question 13

Which of the following is true about the resistance of a thermistor as temperature increases?

Accepted Answer

Resistance decreases with temperature.

Question 14

In a potential divider circuit, what happens to the output voltage if the resistance of the lower resistor is increased, assuming the supply voltage is constant?

Accepted Answer

The output voltage increases.

Question 15

Which of the following best describes the effect of doping a semiconductor with donor atoms?

Accepted Answer

It increases the number of free electrons, enhancing n-type conductivity.

Question 16

What is the main purpose of using a rheostat in a potential divider circuit, as described in the Physics Factsheet?

Accepted Answer

To vary the output voltage by changing the resistance.

Question 17

Which of the following best describes the V-I characteristic of a real ammeter, as discussed in the Physics Factsheet?

Accepted Answer

It has a small resistance and slightly decreases the current in the circuit.

Question 18

According to the Physics Factsheet, what is the effect of increasing the voltage across a filament lamp on its resistance?

Accepted Answer

The resistance increases as voltage increases.

Question 19

Which of the following best describes the behavior of electrons in a metal as charge carriers?

Accepted Answer

Electrons are free to move and act as charge carriers.

Electrons as Charge Carriers and Interpreting V-I Graphs

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