SBA 12
Title: Types of circuits
Problem Statement: John and Sarah decided to make their own fairy lights for Christmas. Sarah
suggested that the bulbs be wired in series. John argued that the current in series is not the same
and the bulbs would not light with the same brightness. Develop a hypothesis and design an
experiment to test the hypothesis.
Hypothesis (conditional tense): A prediction of the outcome of the experiment. The
statement/hypothesis MUST be testable.
Bulbs in series does not have the same brightness while bulbs in parallel have the same
brightness.
Aim:
To determine the brightness in series and parallel circuits.
Apparatus/Materials: list ALL possible apparatus/materials that you may use to conduct the
experiment e.g. Water, nail, petri dish…
Method (present tense):
1. Must be written in present tense and in the form of an instruction eg.
2. Measure 50 cm3 of water by using a measuring cylinder.
3. Do not use any pronouns eg. I, You, We.
4. Use a numbering format to write the method.
5. Must include a time period for experiment.
6. Must state what kind of measurements should be taken for observations.
7. Must mention the use of a CONTROL in the method. A control is a separate
experimental set up in which the factor(s) that is causing a change in the actual
experiment is absent.
Diagram:
Variables: A variable is any factor or item in an experiment that you can control or change.
(i) Manipulated variable (independent variable) – an item or factor that you are purposely
changing in the experiment.
(ii) Responding variable (dependent variable)- the factor that is affected by a change in the
manipulated variable.
(iii) Controlled variable – the items or factors that must be kept the same during the experiment.
Include at least two examples.
Expected Results (conditional tense):
Describe what you would expect to observe in each experimental setup and the reasons for your
answer. Include a table for display of results.
Limitations (conditional tense): Any factor/condition which could have negatively affected the
results. Give an explanation of how the limitation would affect the experiment.
Precautions (conditional tense): Actions to take to avoid injury or harm during the
experiment.
SBA # 12 Current Skills assessed/D (Planning and Designing)
Criteria Total Marks
marks obtained
Hypothesis 2
a. Clearly stated
b. Can be tested
Aim well defined, precise and clear 1
Apparatus and Materials 2
a. 1 item missing (-1 mark)
Method: 3
a. Method outlined properly to give a clear outline of steps. No
steps misplaced or skipped (1 mark)
b. Measurements to be taken are quantified where necessary
(1 mark)
c. Method clearly states how observations are taken (1 mark)
Expected results: 4
a. All expected observations of clearly stated = 2 marks (-1 for
any missing observation)
b. Units are clearly indicated (1 mark)
c. Necessary calculations are stated or Formula (1 mark)
Variables stated: 4
a. Independent variables stated correctly (1 mark)
b. Dependent variables stated correctly (1 mark)
c. At least two controlled variables stated (2 marks)
Possible limitations/Precaution/Source of errors 2
(Any two parameters stated correctly=2 marks)
Total 18
*Weighted marks 10
SBA 13
Title: Resistance
Problem Statement: Mel and Sam decided to build a circuit but only had a 50V battery, 2A filament
bulbs, a lab rheostat resistor, wires, and an ammeter. Mel suggested they use the rheostat to
manipulate the resistance in the circuit since this would help to increase the speed of the motor.
Sam disagreed. Develop a hypothesis to prove/ disapprove Mel’s stand.
Hypothesis (conditional tense): A prediction of the outcome of the experiment. The
statement/hypothesis MUST be testable.
Bulbs in series does not have the same brightness while bulbs in parallel have the same
brightness.
Aim:
To determine the brightness in series and parallel circuits.
Apparatus/Materials: list ALL possible apparatus/materials that you may use to conduct the
experiment e.g. Water, nail, petri dish…
Method (present tense):
8. Must be written in present tense and in the form of an instruction eg.
9. Measure 50 cm3 of water by using a measuring cylinder.
10. Do not use any pronouns eg. I, You, We.
11. Use a numbering format to write the method.
12. Must include a time period for experiment.
13. Must state what kind of measurements should be taken for observations.
14. Must mention the use of a CONTROL in the method. A control is a separate
experimental set up in which the factor(s) that is causing a change in the actual
experiment is absent.
Diagram:
Variables: A variable is any factor or item in an experiment that you can control or change.
(iv) Manipulated variable (independent variable) – an item or factor that you are purposely
changing in the experiment.
(v) Responding variable (dependent variable)- the factor that is affected by a change in the
manipulated variable.
(vi) Controlled variable – the items or factors that must be kept the same during the experiment.
Include at least two examples.
Expected Results (conditional tense):
Describe what you would expect to observe in each experimental setup and the reasons for your
answer. Include a table for display of results.
Limitations (conditional tense): Any factor/condition which could have negatively affected the
results. Give an explanation of how the limitation would affect the experiment.
Precautions (conditional tense): Actions to take to avoid injury or harm during the
experiment.
SBA # 13 Resistance Skills assessed/D (Planning and Designing)
Criteria Total Marks
marks obtained
Hypothesis 2
c. Clearly stated
d. Can be tested
Aim well defined, precise and clear 1
Apparatus and Materials 2
b. 1 item missing (-1 mark)
Method: 3
d. Method outlined properly to give a clear outline of steps. No
steps misplaced or skipped (1 mark)
e. Measurements to be taken are quantified where necessary
(1 mark)
f. Method clearly states how observations are taken (1 mark)
Expected results: 4
d. All expected observations of clearly stated = 2 marks (-1 for
any missing observation)
e. Units are clearly indicated (1 mark)
f. Necessary calculations are stated or Formula (1 mark)
Variables stated: 4
d. Independent variables stated correctly (1 mark)
e. Dependent variables stated correctly (1 mark)
f. At least two controlled variables stated (2 marks)
Possible limitations/Precaution/Source of errors 2
(Any two parameters stated correctly=2 marks)
Total 18
*Weighted marks 10
