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## Chapter 22 – Electromagnetic Induction

1.    Describe an experiment to demonstrate electromagnetic induction. Explain the principles behind the phenomena. What variations in your experiment can you include to demonstrate the factors which affect the magnitude and the direction of the induced emf. When a magnet is pushed into the solenoid, there is a change in magnetic field lines linking the …

## Chapter 21 – Electromagnetism

1.    In an electromagnet, adjusting the variable resistor alters the size of the current. Explain the effect on the strength of the electromagnet. Increasing the resistance of the variable resistance will decrease the current flowing through the wire which will decrease the size of the magnetic strength of the electromagnet.        What other methods are …

## Chapter 20 – Magnetism

1.    State the properties of a magnet. A magnet can attract another magnetic material such as iron, steel, cobalt and nickel. A magnet has two poles, the North pole and South pole. Like poles repel and unlike poles attract. A freely suspended magnet always points in a North-South direction.  2.    With the aid of a …

## Chapter 19 – Practical Electricity

1.    Explain why the metal case of electrical equipment which is operated from the mains supply should be earthed. If the live wire touches the metal casing accidentally, current will flow through the casing and the user touching the casing will get an electrical shock. The earth wire has a resistance much lower than the …

## Chapter 18 – D.C. Circuits

1. Explain why electric lights in a building are connected in parallel rather than in series. When the bulbs are connected in parallel, the current through each bulb will be higher and hence each bulb will glow more brightly. Parallel arrangement also allows the bulbs to work independently. That is, when one bulb is fused …

## Chapter 17 – Current Electricity

1.    Describe an experiment to determine the resistance of a resistor. Set up the apparatus as show in the diagram above. Adjust the rheostat to the maximum so that the smallest possible current flows in the circuit. Record the ammeter reading (I) and the voltmeter reading (V). Adjust the rheostat to allow a larger current …

## Chapter 16 – Static Electricity

1.    How does an ebonite rod become negatively charged when it is rubbed with a duster? What is the charge of the duster and how does it acquire that charge? The ebonite rod gains electron from the duster and becomes negatively charged as it now has an excess of electrons. The duster lose electrons to …

## Chapter 15 – Sound

1.    Describe how a vibrating object produces sound waves. (2 marks) Sound is produced by vibrating sources placed in a medium. When the object (e.g. ruler or tuning fork) vibrates, a series of compressions (high air pressure) and rarefactions (low air pressure) are produced by shifting of air layers. In doing so, a longitudinal wave …

## Chapter 14 – Electromagnetic Wave

Cchapter 14 Electromagnetic Wave 1.    State the properties which are common to all forms of electromagnetic radiation. All are transverse waves. All travel with the same speed, 3 x 10^8 m/s in vacuum. They all obey the wave equation: They can be reflected or refracted They transports energy. 2.    How do the frequency, wavelength and …

## Chapter 13 – Waves

1.    A transverse wave can be demonstrated using a rope. Describe how the hand must move to make a transverse wave of frequency 5 Hz. For a transverse wave to move from left to right, the hand must move in a to and fro motion vertically. There should be 5 oscillations of the hand in …