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JPN Pahang Teacher’s Guide
Physics Module Form 5 Chapter 7: Electricity
CHAPTER 7: ELECTRICITY
7.1 CHARGE AND ELECTRIC CURRENT
Van de Graaf
1. What is a Van de Graaff generator? Fill in each of the boxes the name of the part shown. A device that produces and store electric charges at high voltage on its dome
+ + + + roller
+
+
+ + + +
Metal dome dome
rubber belt roller
motor
-1-
JPN Pahang Teacher’s Guide
Physics Module Form 5 Chapter 7: Electricity
2. How are electrical charges produced by a Van de Graaff generator? And what type of charges is usually produced on the dome of the generator? When the motor of the Van de Graaff generator is switched on, it drives the rubber belt. This causes the rubber belt to against the roller and hence becomes charged. The charge is then carried by the moving belt up to the metal dome where it is collected. A large amount of charge is built up on the dome Positive charges are usually produced on the dome of the generator.
+ 3. What will happen if the charged dome of the Van de Graaff is connected to the earth via a micrometer? Explain. There is a deflection of the pointer of the meter. This indicates an electric current flow. +
+ + +
+ +
-2-
JPN Pahang Teacher’s Guide
Physics Module Form 5 Chapter 7: Electricity
4. Predict what will happen if a discharging metal sphere to the charged dome. + + When the discharging metal sphere is brought near the charged dome, + + + + +
sparkling occurs. An electric current flow.
5.
Predict what will happen if hair of a student is brought near to the charged dome. Give reasons for your answer. The metal dome attracts the hair and the hair stand upright. This is because of each strand of hair receives positive charges and repels each other.
6. The flow of electrical charges produces electric current.
JPN Pahang Teacher’s Guide
Physics Module Form 5 Chapter 7: Electricity
Electric Current
Physics Module Form 5 Chapter 7: Electricity
CHAPTER 7: ELECTRICITY
7.1 CHARGE AND ELECTRIC CURRENT
Van de Graaf
1. What is a Van de Graaff generator? Fill in each of the boxes the name of the part shown. A device that produces and store electric charges at high voltage on its dome
+ + + + roller
+
+
+ + + +
Metal dome dome
rubber belt roller
motor
-1-
JPN Pahang Teacher’s Guide
Physics Module Form 5 Chapter 7: Electricity
2. How are electrical charges produced by a Van de Graaff generator? And what type of charges is usually produced on the dome of the generator? When the motor of the Van de Graaff generator is switched on, it drives the rubber belt. This causes the rubber belt to against the roller and hence becomes charged. The charge is then carried by the moving belt up to the metal dome where it is collected. A large amount of charge is built up on the dome Positive charges are usually produced on the dome of the generator.
+ 3. What will happen if the charged dome of the Van de Graaff is connected to the earth via a micrometer? Explain. There is a deflection of the pointer of the meter. This indicates an electric current flow. +
+ + +
+ +
-2-
JPN Pahang Teacher’s Guide
Physics Module Form 5 Chapter 7: Electricity
4. Predict what will happen if a discharging metal sphere to the charged dome. + + When the discharging metal sphere is brought near the charged dome, + + + + +
sparkling occurs. An electric current flow.
5.
Predict what will happen if hair of a student is brought near to the charged dome. Give reasons for your answer. The metal dome attracts the hair and the hair stand upright. This is because of each strand of hair receives positive charges and repels each other.
6. The flow of electrical charges produces electric current.
JPN Pahang Teacher’s Guide
Physics Module Form 5 Chapter 7: Electricity
Electric Current