Electromagnetic Waves - SS2 Physics Past Questions and Answers - page 3
The speed of light in a vacuum is approximately 3 × 108 m/s. What is the wavelength of an electromagnetic wave with a frequency of 2 × 1015 Hz?
We can use the equation λ = c/f
Substituting the values, λ = (3 × 108 m/s)/(2 × 1015 Hz).
Simplifying the expression, λ = 1.5 × 10-7 m or 150 nm.
An electromagnetic wave has a wavelength of 500 nm. What is the frequency of the wave?
We can use the equation f = c/λ
Substituting the values, f = (3 × 108 m/s)/(500 × 10-9 m).
Simplifying the expression, f = 6 × 1014 Hz.
An electromagnetic wave has a frequency of 1012 Hz. What is the energy of one photon of this wave?
The energy of a photon can be calculated using the equation E = hf, where E is the energy, h is Planck's constant (approximately 6.63 × 10-34 J·s), and f is the frequency
Substituting the values, E = (6.63 × 10-34 J·s) × (1012 Hz).
Simplifying the expression, E = 6.63 × 10-22 J.
Which of the following applications uses radio waves for communication?
Microwave ovens
X-ray machines
AM/FM radio broadcasting
Satellite television
Which of the following applications uses microwaves for heating food?
Radar systems
Wireless communication
MRI scanning
Microwave ovens
Which of the following devices uses radio waves for long-distance communication?
Bluetooth headsets
Cordless phones
Wi-Fi routers
Cellphones
Which of the following applications uses microwaves for weather forecasting?
GPS navigation
Satellite television
Doppler radar
Wi-Fi communication
Which of the following applications uses radio waves for remote sensing and imaging of Earth's surface?
GPS navigation
Weather satellites
Mobile phones
Wi-Fi communication
Discuss the applications of radio waves in communication systems. Provide examples and explain how radio waves are used for various purposes.
Radio waves are extensively used in communication systems for various purposes. AM/FM radio broadcasting is one of the prominent applications where radio waves are used to transmit audio signals over long distances. Radio waves are also employed in television broadcasting, allowing the transmission of visual and audio signals. Additionally, radio waves are used in mobile communication networks, enabling wireless communication between devices such as cell phones. Another application is radar systems, which use radio waves for detecting and tracking objects, including aircraft, ships, and weather patterns.
Explain the role of microwaves in modern technology. Discuss their applications in fields such as cooking, communication, and weather forecasting.
Microwaves play a crucial role in various areas of modern technology. In cooking, microwave ovens utilize microwaves to heat food quickly and efficiently. Microwaves are also used in wireless communication systems, including satellite communication, Wi-Fi networks, and Bluetooth devices. They enable the transmission of data and signals over short and long distances. Furthermore, microwaves are utilized in weather forecasting through the use of weather radar systems. These systems use microwaves to detect precipitation and analyze weather patterns, aiding in accurate forecasting.