Warning: foreach() argument must be of type array|object, bool given in /var/www/html/web/app/themes/studypress-core-theme/template-parts/header/mobile-offcanvas.php on line 20

A sinusoidal electromagnetic wave emitted by a cellular phone has a wavelength of 35.4 cm and an electric-field amplitude of5.40×10-2V/m at adistance of 250 m from the phone. Calculate (a) the frequency of the wave; (b) the magnetic-field amplitude; (c) the intensity of the wave.

Short Answer

Expert verified

a. The frequency of wave is 8.74×108Hz.

b. The amplitude of magnetic-field is 1.8×10-10T.

c. The intensity of wave is 3.87×10-6W/m2.

Step by step solution

01

Define the intensity ( I ) and the formulas.

The power transported per unit area is known as the intensity ( I ).

The formula used to calculate the intensity( I ) is:

I=PA

Where,A is area measured in the direction perpendicular to the energy andP is the power in watts.

The relation between the frequency of wave f, wavelengthλ and speed of lightc is:

c=fλ

And also, I=12ε0cEmax2 . Where, I is the intensity in W/m2and is the speed of light that is equal to 3.0×108m/sand ε0=8.85×10-12C2/N·m2.

The relation between the maximum electric field and maximum magnetic field is:

Bmax=Emaxc

02

Determine frequency of wave.

Given that,λ=35.4×10-2m

The frequency of wave is:

f=cλ=3×10835.4×10-2=8.47×108Hz

Hence, the frequency of wave is 8.47×108Hz.

03

Determine the amplitude of magnetic field.

Given that,Emax=5.4×10-2V/m

The amplitude of magnetic field is:

Bmax=Emaxc=5.4×10-23×108=1.8×10-10T

Hence, the amplitude of magnetic-field is 1.8×10-10T.

04

Determine the intensity of wave.

The intensity of wave:

I=12ε0cEmax2=12×8.854×10-123×1085.4×10-2=3.87×10-6W/m2

Hence, intensity of wave is 3.87×10-6W/m2.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

The definition of resistivity (ρ=EJ) implies that an electrical field exist inside a conductor. Yet we saw that in chapter 21 there can be no electrostatic electric field inside a conductor. Is there can be contradiction here? Explain.

Electric eels generate electric pulses along their skin that can be used to stun an enemy when they come into contact with it. Tests have shown that these pulses can be up to 500V and produce currents of 80mA(or even larger). A typical pulse lasts for 10ms. What power and how much energy are delivered to the unfortunate enemy with a single pulse, assuming a steady current?

In the circuit shown in Fig. E25.30, the 16.0-V battery is removed and reinserted with the opposite polarity, so that its negative terminal is now next to point a. Find (a) the current in the circuit (magnitude anddirection); (b) the terminal voltage Vbaof the 16.0-V battery; (c) the potential difference Vacof point awith respect to point c. (d) Graph the potential rises and drops in this circuit (see Fig. 25.20).

When a resistor with resistance Ris connected to a 1.50-V flashlight battery, the resistor consumes 0.0625 W of electrical power. (Throughout, assume that each battery has negligible internal resistance.) (a) What power does the resistor consume if it is connected to a 12.6-V car battery? Assume that Rremains constant when the power consumption changes. (b) The resistor is connected to a battery and consumes 5.00 W. What is the voltage of this battery?

(See Discussion Question Q25.14.) Will a light bulb glow more brightly when it is connected to a battery as shown in Fig. Q25.16a, in which an ideal ammeter is placed in the circuit, or when it is connected as shown in Fig. 25.16b, in which an ideal voltmeter V is placed in the circuit? Explain your reasoning.

See all solutions

Recommended explanations on Physics Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free