A radio can tune in to any station in the 7.5 MHz to 12 MHz band. What is the corresponding wavelength band?
A radio can tune in to any station in the 7.5 MHz to 12 MHz band. What is the corresponding wavelength band?
Solution and Explanation
A radio can tune to minimum frequency, \(ν_1 = 7.5 \ MHz= 7.5 × 10^6 Hz \)
Maximum frequency, \(ν_2 = 12\ MHz = 12 × 10^6 Hz \)
Speed of light, \(c = 3 × 10^8 \ m/s \)
Corresponding wavelength for \(ν_1\) can be calculated as:
\(λ_1 = \frac {c}{v_1}\)
\(λ_1 = \frac {3\times 10^8}{7.5\times 10^6 }= 40 \ m\)
Corresponding wavelength for \(ν_2\) can be calculated as:
\(λ_2 = \frac {c}{v_2}\)
\(λ_2 = \frac {3\times 10^8}{12\times 10^6 }= 25 \ m\)
Thus, the wavelength band of the radio is \(40 \ m\) to \(25 \ m\).
Top Questions on Electromagnetic Waves
- An electromagnetic wave is travelling in vertically upward direction. At an instant, its electric field vector points in west direction. In which direction does the magnetic field vector point at that instant?
- CBSE CLASS XII - 2025
- Physics
- Electromagnetic Waves
- X-rays are more harmful to human beings than ultraviolet radiations because X-rays:
- CBSE CLASS XII - 2025
- Physics
- Electromagnetic Waves
- Estimate the ratio of shortest wavelength of radio waves to the longest wavelength of gamma waves.
- CBSE CLASS XII - 2025
- Physics
- Electromagnetic Waves
- How is an electromagnetic wave produced?
- CBSE CLASS XII - 2025
- Physics
- Electromagnetic Waves
- The electric field in a plane electromagnetic wave is given by \(E_z = 60 \cos(5x + 1.5 \times 10^{10} t)\) V/m. Then expression for the corresponding magnetic field (\(B_y\)) is (here subscripts denote the direction of the field) is:
- NEET (UG) - 2025
- Physics
- Electromagnetic Waves
Questions Asked in CBSE CLASS XII exam
A ladder of fixed length \( h \) is to be placed along the wall such that it is free to move along the height of the wall.
Based upon the above information, answer the following questions:(i)} Express the distance \( y \) between the wall and foot of the ladder in terms of \( h \) and height \( x \) on the wall at a certain instant. Also, write an expression in terms of \( h \) and \( x \) for the area \( A \) of the right triangle, as seen from the side by an observer.
- CBSE CLASS XII - 2025
- Application of derivatives
- A charge \( -6 \mu C \) is placed at the center B of a semicircle of radius 5 cm, as shown in the figure. An equal and opposite charge is placed at point D at a distance of 10 cm from B. A charge \( +5 \mu C \) is moved from point ‘C’ to point ‘A’ along the circumference. Calculate the work done on the charge.
- CBSE CLASS XII - 2025
- Electrostatics
- Charlie’s desperate attempt to find the third level reflects his frustration with the modern world. Substantiate the above statement with evidence from the story. (The Third Level)
निम्नलिखित गद्यांश की सप्रसंग व्याख्या कीजिए :
‘‘पुर्ज़े खोलकर फिर ठीक करना उतना कठिन काम नहीं है, लोग सीखते भी हैं, सिखाते भी हैं, अनाड़ी के हाथ में चाहे घड़ी मत दो पर जो घड़ीसाज़ी का इम्तहान पास कर आया है उसे तो देखने दो । साथ ही यह भी समझा दो कि आपको स्वयं घड़ी देखना, साफ़ करना और सुधारना आता है कि नहीं । हमें तो धोखा होता है कि परदादा की घड़ी जेब में डाले फिरते हो, वह बंद हो गई है, तुम्हें न चाबी देना आता है न पुर्ज़े सुधारना तो भी दूसरों को हाथ नहीं लगाने देते इत्यादि ।’’
- CBSE CLASS XII - 2025
- सप्रसंग व्याख्या
- Draw the structure of the major monohalo product for each of the following reactions:
- CBSE CLASS XII - 2025
- Haloalkanes And Haloarenes
Concepts Used:
Electromagnetic Spectrum
The term used by scientists to describe the entire range of light that exists is the electrostatic spectrum. Light is a wave of alternating electric and magnetic fields. The propagation of light doesn't vary from waves crossing an ocean. Like any other wave, light also has a few fundamental properties that describe it. One is its frequency. The frequency is measured in Hz, which counts the number of waves that pass by a point in one second.
The electromagnetic waves that your eyes detect are visible light and oscillate between 400 and 790 terahertz (THz). That’s several hundred trillion times a second.