First 230 words of the document:
This sheet looks at the current-voltage (I-V) curves for a fixed resistor, a filament
bulb and a semiconductor diode.
If you know the current through and voltage across an electrical component
write down the formula used to find:
a) the component's resistance and
b) the power dissipated in the component.
1. The fixed resistor
1. Sketch the I-V curve for a fixed
2. A fixed resistor has current of 12
mA when the potential difference is 2.5
V. What is the resistance of this resistor?
3. What current will flow with a pd of:
a. 6 V
b. -2.5 V
c. -0.2 V
d. 48 kV
4. What voltage is needed to generate
a current of
a. 1 A
b. 60 mA
5. What is the resistance of the
a. 60 V, b. 0.1 V, c. 679.4 V
6. Fixed resistors are said to be
`ohmic'. What does this mean?
On the axes to the left sketch
a) the I-V curve for an ohmic resistor
that has very high resistance. Label this
line `high R'.
b) the I-V curve for an ohmic resistor
that has low resistance. Label this line
c) Explain how you made your choice.
Other pages in this set
Here's a taster:
The filament bulb
1. Is this component ohmic? Explain your answer
2. Describe the characteristic
3. What is happening to the resistance of the filament as the pd applied
increases? How does this affect the current flowing?
4. Find the resistance when the pd is
a. 2 V
b. 6 V
c. 8 V
d. 8 V
5. The component still has resistance when V = 0. How can you find this
6. What is the resistance at V = 0?
Here's a taster:
The semiconductor diode
1. Sketch the I-V characteristic for a semiconductor diode. Indicate any
2. Describe the characteristic shown by the graph
3. What is meant by forward bias?
4. What is meant by reverse bias?
5. How does the resistance of the diode vary with an increase in voltage in
a) forward bias
b) reverse bias
6. Why must care be taken when increasing the voltage in the forward bias