Learning Objectives (стр. 9 )

Resistance in ohms = ................................................

[2]

(b) What is the percentage tolerance of the resistor R?

....................................................................................

[1]

(c) What is the tolerance in ohms of the resistor R?

....................................................................................

[1]

8. Here is a diagram of an 82Ω ±5% resistor.

(a) Complete the following table.

Resistor Value	Colour of Band 1	Colour of Band 2	Colour of Band 3	Colour of Band 4
82Ω

[4]

(b) The 82Ω resistor is now placed in parallel with an 18Ω resistor. Calculate the combined resistance.

..............................................................................................................................................

..............................................................................................................................................

[2]

9. Here is a list of four mechanical switches:

push, reed, tilt, toggle

Choose the most appropriate switch from the list for the following jobs.

(a) To warn tractor drivers that the tractor may be in danger of toppling over.

Answer : ................................................

(b) To be used with a magnet to sense when a door is open.

Answer : ................................................

[2]

10. Here is a voltage divider.

(a) What is the combined resistance of R1 and R2?

.................................................................................................................................................

[1]

(b) Calculate the value of the voltage VOUT.

..............................................................................................................................................

..............................................................................................................................................

[2]

11. Three resistors are arranged as a voltage divider as follows:

(a) Calculate the combined resistance of the 10kΩ and 15kΩ resistors.

..............................................................................................................................................

..............................................................................................................................................

[2]

(b) Calculate the output voltage VOUT.

..............................................................................................................................................

..............................................................................................................................................

[1]

11. The resistor colour code is given in the information sheet on page 2.

(a) Use the information to work out the colour code for a 10kΩ resistor.

Write the colours in the correct spaces on the diagram below.

[3]

(b) Use the colour code to work out the resistance of the following resistor.

(i) Resistance in ohms = ..................................

[2]

(ii) Use the tolerance band to calculate the highest and lowest values the resistor could have.

Highest Value in ohms = .........................................

Lowest Value in ohms = ..........................................

[2]

(c) The 10kΩ resistor is used with a 5kΩ resistor to make a voltage divider:

(i) What is the combined resistance of R1 and R2?

.....................................................................................................................................

[1]

(ii) Calculate the value of the voltage, VOUT.

.....................................................................................................................................

.....................................................................................................................................

[2]

Self Evaluation Review

Learning Objectives	My personal review of these objectives:
J	K	L
1.4.1 Resistors
understand that resistance can be increased by connecting resistors in series;
understand that resistance can be decreased by connecting resistors in parallel;
select and use the equation to perform calculations involving the combined resistance of two resistors in series;
select and use the equation to perform calculations involving the combined resistance of two resistors in parallel;
describe how fixed and variable resistors can be used in voltage dividers;
describe how potentiometers can be used as variable resistors and voltage dividers;
use the colour and printed code to work out the value and tolerance of a resistor;
select appropriate preferred values from the E24 series;
1.4.2 Light Dependent Resistors (LDRs)
state that the resistance of an LDR falls as light intensity increases (non-linear);
1.4.3 NTC Thermistors
state that the resistance of ntc thermistors decreases as temperature increases (non-linear);
1.4.4 SWITCHES
distinguish between the following types of mechanical switches: push, toggle, reed, micro, tilt, rotary

Targets: 1. ………………………………………………………………………………………………………………

………………………………………………………………………………………………………………

2.  ………………………………………………………………………………………………………………

………………………………………………………………………………………………………………