BTEC Applied Science - Physics Exam Questions

BTEC Applied Science - Physics Exam Questions State what is meant by the term analogue signal (1 mark) - A signal that can have any value State what is meant by the term digital signal (1 mark) - A signal that has 2 values only which are 0 and 1. Explain 2 advantages of using digital signals instead of analogue signals to transmit television programmes. (2 marks) - 1. Digital Signals can carry more info than Analogue signals. 2. Less interference so better quality is produced. Give 2 other differences between visible light waves and sound waves. (2 marks) - 1. Visible light is electromagnetic whereas sound is a vibration 2. Sound waves has a lower frequency than visible light. Explain the advantages and disadvantages of using radio waves instead of light waves to send large amounts of information from the satellite to the surface of the Earth. (4 marks) - 1. Light waves have a higher frequency than radio waves so light waves would take less time to transfer information. 2. Some of the radio waves reach the Earth's surface so they receive a clear signal. Evaluate the strengths and weaknesses of using: • An infrared remote control • A Bluetooth remote control to control the home cinema system. (6 marks) - 1. Infrared doesn't interfere with other devices - has higher frequency than Bluetooth 2. This means there will be better quality between the devices. 3. Infrared is not able to transmit through most materials. 4. Bluetooth can be used on more than 1 device. 5. Can work through walls. 6. It can interfere with other Bluetooth devices if close by. Describe how a longitudinal wave is produced on a slinky spring. (2 marks) - The slinky is pushed and pulled paralell to the direction of wave Explain why a mobile phone might not receive a signal when in range of a neurotransmitter. (2 marks) - Being below ground level can cause attenuation.