Q21.The speed of a swimmer is 4 km h-1 in still water. If the swimmer makes his strokes normal to the flow of river of width 1 km, he reaches a point 750 m down the stream on the opposite bank. The speed of the river water is ______ km h-1.
What This Question Tests
This question asks to identify the frequencies present in an amplitude modulated signal given the carrier and modulating signal equations, testing knowledge of carrier and sideband frequencies.
Concepts Tested
Formulas Used
f_c = ω_c / (2π)
f_m = ω_m / (2π)
f_USB = f_c + f_m
f_LSB = f_c - f_m
📚 NCERT Sections This Tests
14.4 — The Speed Of A Travelling
Physics Class 12 · Chapter 14
14.4 The speed of a travelling a circle. If you continue dropping pebbles in the pond, you wave see circles rapidly moving outward from the point where the
10.1 — Monochromatic Light Of Wavelength 589 Nm Is Incident From Air On A
Physics Class 12 · Chapter 10
10.1 Monochromatic light of wavelength 589 nm is incident from air on a water surface. What are the wavelength, frequency and speed of (a) reflected, and (b) refracted light? Refractive index of water is 1.33.
12.6 — (A) 2.18 × 106 M/S; 1.09 × 106 M/S; 7.27 × 105 M/S
Physics Class 12 · Chapter 12
12.6 (a) 2.18 × 106 m/s; 1.09 × 106 m/s; 7.27 × 105 m/s (b) 1.52 × 10–16 s; 1.22 × 10–15 s; 4.11 × 10–15 s.
📋 Question Details
- Chapter
- Communication Systems
- Topic
- Amplitude Modulation
- Year
- 2023
- Shift
- 31 Jan Shift 1
- Q Number
- Q21
- Type
- MCQ
- NCERT Ref
- Class 12 Physics Ch 15: Communication Systems
More from this Chapter
Q78.Consider telecommunication through optical fibres. Which of the following statements is not true? (1) Optical fibres can be of graded refractive index (2) Optical fibres are subjective to electromagnetic interference from outside (3) Optical fibres have extremely low transmission (4) Optical fibres may have homogeneous core with loss a suitable cladding.
Q29.This question has Statement −1 and Statement −2. Of the four choices given after the statements, choose the one that best describes the two statements. Statement-1 : Sky wave signals are used for long distance radio communication. These signals are in general, less stable than ground wave signals. Statement-2 : The state of ionosphere varies from hour to hour, day to day and season to season. (1) Statement-1 is true, Statement-2 is true; (2) Statement-1 is true, Statement-2 is true; Statement-2 is the correct explanation of Statement-2 is not the correct explanation of Statement-1. Statement-1. (3) Statement- 1 is false, Statement- 2 is true. (4) Statement-1 is true, Statement-2 is false. JEE Main 2011 JEE Main Previous Year Paper
Q30.Broadcasting antennas are generally (1) vertical type (2) both vertical and horizontal type (3) omni directional type (4) horizontal type
Q29.Given the electric field of a complete amplitude modulated wave as Em →E = ^iEc + cos cos ωct (1 Ec ωmt) Where the subscript c stands for the carrier wave and m for the modulating signal. The frequencies present in the modulated wave are (1) ωc and √ω2c + ω2m (2) ωc, ωc + ωm and ωc −ωm (3) ωc and ωm (4) ωc and √ωcωm