3.30 describe an experiment using an oscilloscope to determine the frequency of a sound wave Experiment: To determine the frequency of a sound wave Sound is produced by a loudspeaker. The microphone catches the sound and transmits it into electrical signal. The...
3.31 relate the pitch of a sound to the frequency of vibration of the source The more something vibrates the higher frequency. The higher frequency, the higher pitch. So the more vibrations the higher pitch.
3.32 relate the loudness of a sound to the amplitude of vibration. The bigger the vibration the higher the amplitude. The higher the amplitude the louder the sound.
3.29 understand how an oscilloscope and microphone can be used to display a sound wave When sound waves enter the mircrophone, they make a crystal or a metal plate inside it vibrate. The vibrations are changed into electrical signals, and the oscilloscope uses these...
3.26 understand that sound waves are longitudinal waves and how they can be reflected, refracted and diffracted Sound waves are longitudinal waves. Like other waves they can also be reflected refracted and diffracted. Sound waves reflect when they bounce back from a...
3.27 understand that the frequency range for human hearing is 20 Hz – 20,000 Hz An average person can only hear sound that have a frequency higher than 20Hz but lower than 20000 Hz. This spread of frequency is called audible range. Frequency higher than 20000 Hz which...
3.28 describe an experiment to measure the speed of sound in air Experiment: To measure the speed of sound by direct method Apparatus: Starting pistol, stopwatch, measuring tape. Procedure: By means of measuring tape, observers are positioned at known distance apart...
3.18 know and use the relationship between refractive index, angle of incidence and angle of refraction The ratio between sine of the angle of incidence and the sine of the angle of refraction is called refractive index. In a material, the refractive index is constant...
3.23 understand the difference between analogue and digital signals To send a message using a digital signal, the information is converted into a sequence of numbers called a binary code. Digital electrical signals can either have of only two possible values...
3.24 describe the advantages of using digital signals rather than analogue signals Regenerating digital signal creates a clean accurate copy of the orginal signal but analogue signal are corrupted by other signals. With digital signal, you can broadcast programs over...
3.25 describe how digital signals can carry more information Digital signals are capable of carrying more information than analogue signals because digital signals make use of the bandwidth more efficiently by closely approximating the original analogue signal. The...
3.20 describe the role of total internal reflection in transmitting information along optical fibres and in prisms Total internal reflection: When light falls on the surface of a lighter medium from denser medium at an angle of incidence greater than critical angle,...
3.21 explain the meaning of critical angle c Critical angle is an incident angle at which the incident ray is refracted and the refracted angle is equal to 90 degree in condition that the light falls on the surface of a lighter medium from denser medium.
3.22 know and use the relationship between critical angle and refractive index sin c = 1/n sin (critical angle) = 1/ refractive index
3.19 describe an experiment to determine the refractive index of glass, using a glass block Experiment: To determine the refractive index of glass, using a glass block. Put the glass block on an wooden table which is passed by a white sheet. The border of the...
3.17 describe experiments to investigate the refraction of light, using rectangular blocks, semicircular blocks and triangular prisms As a light ray passes from one transparent medium to another, it bends. This bending of light is called refraction. Refraction occurs...
3.15 use the law of reflection (the angle of incidence equals the angle of reflection) The law of reflection states that: The incident ray, reflected ray and normal all lie in the same plane. The angle of incidence is equal to the angle of reflection.
3.16 construct ray diagrams to illustrate the formation of a virtual image in a plane mirror Types of images: Virtual images: Image through which the rays of light don’t not actually pass is called virtual image. Example: Image formed in the mirror. Virtual images...
3.11 identify the order of the electromagnetic spectrum in terms of decreasing wavelength and increasing frequency, including the colours of the visible spectrum The list follows with increasing frequency and decreasing wavelength. Radio Waves > Microwaves >...
3.14 understand that light waves are transverse waves which can be reflected, refracted and diffracted Light waves are transverse wave that is emitted from luminous or non-luminous objects. Light waves are transverse wave and like all waves, they can be reflected,...
3.13 understand the detrimental effects of excessive exposure of the human body to electromagnetic waves, and describe simple protective measures against the risks Microwaves: Micro waves might cause internal heating of body tissue. For this microwave ovens have metal...
3.12 explain some of the uses of electromagnetic radiations, including Radio waves: It is used in communicating information. This can be speech, radio and television, music and encoded messages like computer data, navigation signals and telephone conversations. The...