Question: A ray of light in air strikes

> Light with a frequency of 5.80 * 1014 Hz travels in a block of glass that has an index of refraction of 1.52. What is the wavelength of the light a. in vacuum and b. in the glass

> The refractive index of a certain glass is 1.66. For what incident angle is light reflected from the surface of this glass completely polarized if the glass is immersed in a. air and b. water?

> We can reasonably model a 75-W incandescent light bulb as a sphere 6.0 cm in diameter. Typically, only about 5% of the energy goes to visible light; the rest goes largely to nonvisible infrared radiation. a. What is the visible-light intensity (in W/m2)

> A beam of light has a wavelength of 650 nm in vacuum. a. What is the speed of this light in a liquid whose index of refraction at this wavelength is 1.47? b. What is the wavelength of these waves in the liquid?

> A parallel beam of unpolarized light in air is incident at an angle of 54.5° (with respect to the normal) on a plane glass surface. The reflected beam is completely linearly polarized. a. What is the refractive index of the glass? b. What is the angle

> A beam of light strikes a sheet of glass at an angle of 57.0° with the normal in air. You observe that red light makes an angle of 38.1° with the normal in the glass, while violet light makes a 36.7° angle. a. What are the indexes of refraction of this

> The vitreous humor, a transparent, gelatinous fluid that fills most of the eyeball, has an index of refraction of 1.34. Visible light ranges in wavelength from 380 nm (violet) to 750 nm (red), as measured in air. This light travels through the vitreous h

> Light enters a solid pipe made of plastic having an index of refraction of 1.60. The light travels parallel to the upper part of the pipe (Fig. E33.15). You want to cut the face AB so that all the light will reflect back into the pipe after it first stri

> A ray of light traveling in water is incident on an interface with a flat piece of glass. The wavelength of the light in the water is 726 nm, and its wavelength in the glass is 544 nm. If the ray in water makes an angle of 56.0° with respect to the norma

> A transformer connected to a 120-V (rms) ac line is to supply 13,000 V (rms) for a neon sign. To reduce shock hazard, a fuse is to be inserted in the primary circuit; the fuse is to blow when the rms current in the secondary circuit exceeds 8.50 mA. a.

> A transformer connected to a 120-V (rms) ac line is to supply 12.0 V (rms) to a portable electronic device. The load resistance in the secondary is 5.00 Ω. a. What should the ratio of primary to secondary turns of the transformer be? b. What rms curren

> You plan to take your hair dryer to Europe, where the electrical outlets put out 240 V instead of the 120 V seen in the United States. The dryer puts out 1600 W at 120 V. a. What could you do to operate your dryer via the 240-V line in Europe? b. What

> In an L-R-C series circuit, L = 0.280 H and C = 4.00µF. The voltage amplitude of the source is 120 V. a. What is the resonance angular frequency of the circuit? b. When the source operates at the resonance angular frequency, the current amplitude in th

> A 200-Ω resistor, 0.900-H inductor, and 6.00-µF capacitor are connected in series across a voltage source that has voltage amplitude 30.0 V and an angular frequency of 250 rad/s. a. What are v, vR, vL, and vC at t = 20.0 ms? Compare vR + vL + vC to v at

> An electromagnetic standing wave in air has frequency 75.0 MHz. a. What is the distance between nodal planes of the E field? b. What is the distance between a nodal plane of E and the closest nodal plane of B?

> A ray of light is incident on a plane surface separating two sheets of glass with refractive indexes 1.70 and 1.58. The angle of incidence is 62.0°, and the ray originates in the glass with n = 1.70. Compute the angle of refraction.

> A standing electromagnetic wave in a certain material has frequency 2.20 * 1010 Hz. The nodal planes of B are 4.65 mm apart. Find a. the wavelength of the wave in this material; b. the distance between adjacent nodal planes of the E field; c. the spee

> In an L-R-C series circuit, R = 300 Ω, L = 0.400 H, and C = 6.00 * 10-8 F. When the ac source operates at the resonance frequency of the circuit, the current amplitude is 0.500 A. a. What is the voltage amplitude of the source? b. What is the amplitude

> An L-R-C series circuit is constructed using a 175-Ω resistor, a 12.5-µF capacitor, and an 8.00-mH inductor, all connected across an ac source having a variable frequency and a voltage amplitude of 25.0 V. a. At what angular frequency will the impedance

> If the eye receives an average intensity greater than 1.0 * 102 W/m2, damage to the retina can occur. This quantity is called the damage threshold of the retina. a. What is the largest average power (in mW) that a laser beam 1.5 mm in diameter can have

> In the 25-ft Space Simulator facility at NASA’s Jet Propulsion Laboratory, a bank of overhead arc lamps can produce light of intensity 2500 W/m2 at the floor of the facility. (This simulates the intensity of sunlight near the planet Venus.) Find the aver

> An intense light source radiates uniformly in all directions. At a distance of 5.0 m from the source, the radiation pressure on a perfectly absorbing surface is 9.0 * 10-6 Pa. What is the total average power output of the source?

> An L-R-C series circuit is connected to a 120-Hz ac source that has Vrms = 80.0 V. The circuit has a resistance of 75.0 Ω and an impedance at this frequency of 105 Ω. What average power is delivered to the circuit by the source?

> A monochromatic light source with power output 60.0 W radiates light of wavelength 700 nm uniformly in all directions. Calculate Emax and Bmax for the 700-nm light at a distance of 5.00 m from the source.

> The resistor, inductor, capacitor, and voltage source described in Exercise 31.14 are connected to form an L-R-C series circuit. a. What is the impedance of the circuit? b. What is the current amplitude? c. What is the phase angle of the source voltag

> A sinusoidal electromagnetic wave emitted by a cellular phone has a wavelength of 35.4 cm and an electric-field amplitude of 5.40 * 10-2 V/m at a distance of 250 m from the phone. Calculate a. the frequency of the wave; b. the magnetic-field amplitude;

> a. Show that for an L-R-C series circuit the power factor is equal to R/Z. b. An L-R-C series circuit has phase angle -31.5o. The voltage amplitude of the source is 90.0 V. What is the voltage amplitude across the resistor?

> The energy flow to the earth from sunlight is about 1.4 kW/m2. a. Find the maximum values of the electric and magnetic fields for a sinusoidal wave of this intensity. b. The distance from the earth to the sun is about 1.5 * 1011 m. Find the total power

> The power of a certain CD player operating at 120 V rms is 20.0 W. Assuming that the CD player behaves like a pure resistor, find a. the maximum instantaneous power; b. the rms current; c. the resistance of this player.

> A sinusoidal electromagnetic wave from a radio station passes perpendicularly through an open window that has area 0.500 m2. At the window, the electric field of the wave has rms value 0.0400 V/m. How much energy does this wave carry through the window d

> In an L-R-C series circuit, the rms voltage across the resistor is 30.0 V, across the capacitor it is 90.0 V, and across the inductor it is 50.0 V. What is the rms voltage of the source?

> A horizontal, parallel- sided plate of glass having a refractive index of 1.52 is in contact with the surface of water in a tank. A ray coming from above in air makes an angle of incidence of 35.0° with the normal to the top surface of the glass. a. Wha

> An electromagnetic wave with frequency 5.70 * 1014 Hz propagates with a speed of 2.17 * 108 m/s in a certain piece of glass. Find a. the wavelength of the wave in the glass; b. the wavelength of a wave of the same frequency propagating in air; c. the

> An electromagnetic wave with frequency 65.0 Hz travels in an insulating magnetic material that has dielectric constant 3.64 and relative permeability 5.18 at this frequency. The electric field has amplitude 7.20 * 10-3 V/m. a. What is the speed of propa

> A 150-Ω resistor is connected in series with a 0.250-H inductor and an ac source. The voltage across the resistor is vR =(3.80 V)cos[(720 rad/s)t]. a. Derive an expression for the circuit current. b. Determine the inductive reactance of the inductor.

> You have a 200-Ω resistor, a 0.400-H inductor, and a 6.00-µF capacitor. Suppose you take the resistor and inductor and make a series circuit with a voltage source that has voltage amplitude 30.0 V and an angular frequency of 250 rad/s. a. What is the im

> A 250-Ω resistor is connected in series with a 4.80-µF capacitor and an ac source. The voltage across the capacitor is vC = (7.60 V)sin[(120 rad/s)t]. a. Determine the capacitive reactance of the capacitor. b. Derive an expression for the voltage vR ac

> A 0.180-H inductor is connected in series with a 90.0-Ω resistor and an ac source. The voltage across the inductor is vL = -(12.0 V)sin[(480 rad/s)t]. a. Derive an expression for the voltage vR across the resistor. b. What is vR at t = 2.00 ms?

> You want the current amplitude through a 0.450-mH inductor (part of the circuitry for a radio receiver) to be 1.80 mA when a sinusoidal voltage with amplitude 12.0 V is applied across the inductor. What frequency is required?

> a. What is the reactance of a 3.00-H inductor at a frequency of 80.0 Hz? b. What is the inductance of an inductor whose reactance is 120 Ω at 80.0 Hz? c. What is the reactance of a 4.00-mF capacitor at a frequency of 80.0 Hz? d. What is the capacitanc

> Two plane mirrors intersect at right angles. A laser beam strikes the first of them at a point 11.5 cm from their point of intersection, as shown in Fig. E33.1. For what angle of incidence at the first mirror will this ray strike the midpoint of the seco

> The wiring for a refrigerator contains a starter capacitor. A voltage of amplitude 170 V and frequency 60.0 Hz applied across the capacitor is to produce a current amplitude of 0.850 A through the capacitor. What capacitance C is required?

> A capacitance C and an inductance L are operated at the same angular frequency. a. At what angular frequency will they have the same reactance? b. If L = 5.00 mH and C = 3.50 µF, what is the numerical value of the angular frequency in part (a), and wha

> An inductor with L = 9.50 mH is connected across an ac source that has voltage amplitude 45.0 V. a. What is the phase angle ɸ for the source voltage relative to the current? Does the source voltage lag or lead the current? b. What value for the frequen

> A capacitor is connected across an ac source that has voltage amplitude 60.0 V and frequency 80.0 Hz. a. What is the phase angle f for the source voltage relative to the current? Does the source voltage lag or lead the current? b. What is the capacitan

> The voltage across the terminals of an ac power supply varies with time according to Eq. (31.1). The voltage amplitude is V = 45.0 V. What are a. the root-mean-square potential difference Vrms and b. the average potential difference Vav between the two

> Radio station WCCO in Minneapolis broadcasts at a frequency of 830 kHz. At a point some distance from the transmitter, the magnetic-field amplitude of the electromagnetic wave from WCCO is 4.82*10-11 T. Calculate a. the wavelength; b. the wave number;

> A sinusoidal current i = I cos ωt has an rms value Irms = 2.10 A. a. What is the current amplitude? b. The current is passed through a full-wave rectifier circuit. What is the rectified average current? c. Which is larger: Irms or Irav? Explain, using

> You have a special light bulb with a very delicate wire filament. The wire will break if the current in it ever exceeds 1.50 A, even for an instant. What is the largest root-mean-square current you can run through this bulb?

> In an L-R-C series circuit, can the instantaneous voltage across the capacitor exceed the source voltage at that same instant? Can this be true for the instantaneous voltage across the inductor? Across the resistor? Explain.

> Sometimes when looking at a window, you see two reflected images slightly displaced from each other. What causes this?

> Suppose that a positive point charge q is initially at rest on the x-axis, in the path of the electromagnetic plane wave described in Section 32.2. Will the charge move after the wave front reaches it? If not, why not? If the charge does move, describe i

> Fluorescent lights often use an inductor, called a ballast, to limit the current through the tubes. Why is it better to use an inductor rather than a resistor for this purpose?

> Sometimes neon signs located near a powerful radio station are seen to glow faintly at night, even though they are not turned on. What is happening?

> Can water waves be reflected and refracted? Give examples. Does Huygens’s principle apply to water waves? Explain.

> The magnetic-field amplitude of the electromagnetic wave from the laser described in Example 32.1 (Section 32.3) is about 100 times greater than the earth’s magnetic field. If you illuminate a compass with the light from this laser, wou

> a. A tank containing methanol has walls 2.50 cm thick made of glass of refractive index 1.550. Light from the outside air strikes the glass at a 41.3° angle with the normal to the glass. Find the angle the light makes with the normal in the methanol. b.

> The light beam from a searchlight may have an electric field magnitude of 1000 V/m, corresponding to a potential difference of 1500 V between the head and feet of a 1.5-m-tall person on whom the light shines. Does this cause the person to feel a strong e

> Devise straightforward experiments to measure the speed of light in a given glass using a. Snell’s law; b. total internal reflection; c. Brewster’s law.

> You are sunbathing in the late afternoon when the sun is relatively low in the western sky. You are lying flat on your back, looking straight up through Polaroid sunglasses. To minimize the amount of sky light reaching your eyes, how should you lie: with

> For the old “rabbit-ear” style TV antennas, it’s possible to alter the quality of reception considerably simply by changing the orientation of the antenna. Why?

> An inductor, a capacitor, and a resistor are all connected in series across an ac source. If the resistance, inductance, and capacitance are all doubled, by what factor does each of the following quantities change? Indicate whether they increase or decre

> It has been proposed that automobile windshields and headlights should have polarizing filters to reduce the glare of oncoming lights during night driving. Would this work? How should the polarizing axes be arranged? What advantages would this scheme hav

> If you sit on the beach and look at the ocean through Polaroid sunglasses, the glasses help to reduce the glare from sunlight reflecting off the water. But if you lie on your side on the beach, there is little reduction in the glare. Explain why there is

> How can you determine the direction of the polarizing axis of a single polarizer?

> A circuit consists of a light bulb, a capacitor, and an inductor connected in series to an ac source. What happens to the brightness of the bulb when the inductor is omitted? When the inductor is left in the circuit but the capacitor is omitted? Explain.

> Does an electromagnetic standing wave have energy? Does it have momentum? Are your answers to these questions the same as for a traveling wave? Why or why not?

> As shown in Fig. E33.11, a layer of water covers a slab of material X in a beaker. A ray of light traveling upward follows the path indicated. Using the information on the figure, find a. the index of refraction of material X and b. the angle the light

> A student claimed that, because of atmospheric refraction (see Discussion Question Q33.2), the sun can be seen after it has set and that the day is therefore longer than it would be if the earth had no atmosphere. First, what does she mean by saying that

> A beam of light goes from one material into another. On physical grounds, explain why the wavelength changes but the frequency and period do not.

> When an L-R-C series circuit is connected across a 120-V ac line, the voltage rating of the capacitor may be exceeded even if it is rated at 200 or 400 V. How can this be?

> In an L-R-C series circuit, what are the phase angle ɸ and power factor cos ɸ when the resistance is much smaller than the from resonance? Explain.

> If you look up from underneath toward the surface of the water in your aquarium, you may see an upside-down reflection of your pet fish in the surface of the water. Explain how this can happen.

> Is it possible for the power factor of an L-R-C series ac circuit to be zero? Justify your answer on physical grounds.

> Sunlight or starlight passing through the earth’s atmosphere is always bent toward the vertical. Why? Does this mean that a star is not really where it appears to be? Explain.

> The current in an ac power line changes direction 120 times per second, and its average value is zero. Explain how it is possible for power to be transmitted in such a system.

> A 45°-45°-90° prism is immersed in water. A ray of light is incident normally on one of its shorter faces. What is the minimum index of refraction that the prism must have if this ray is to be totally reflected within the glass at the long face of the pr

> Optical fibers are constructed with a cylindrical core surrounded by a sheath of cladding material. Common materials used are pure silica (n2 = 1.450) for the cladding and silica doped with germanium (n1 = 1.465) for the core. a. What is the critical an

> The electric field of a sinusoidal electromagnetic wave obeys the equation E =(375 V/m) cos[(1.99 * 107 rad/m)x + (5.97 * 1015 rad/s)t]. a. What is the speed of the wave? b. What are the amplitudes of the electric and magnetic fields of this wave? c. W

> a. How much time does it take light to travel from the moon to the earth, a distance of 384,000 km? b. Light from the star Sirius takes 8.61 years to reach the earth. What is the distance from earth to Sirius in kilometers?

> Which stage of the Lewin model of change do you think is most often overlooked? Why?

> Which sources of resistance to change present the most problems for an internal change agent? For an external change agent?

> What broad category of pressures for organization change other than the four discussed in the chapter can you think of? Briefly describe it.

> Which of the seven keys for successfully managing an organizational change effort seem to be the most difficult to manage? Why?

> Is most organization change forced on the organization by external factors or fostered from within? Explain.

> Describe how you might go about taking advantage of an existing organizational culture

> What current examples can you identify to reflect radical, systems, and incremental innovations?

> How are technology and innovation interrelated?

> What can companies do to create and reinforce a culture of inclusion?

> How do you learn about prospective employers’ cultures? How important is a company’s culture to you when you decide to apply or to accept a job offer?

> What can leaders do to be effective when team members are from different cultures and have different expectations about how the leaders should behave?

> Do you think that culture is important to organizational performance? Why or why not?

> Describe three different types of organizational cultures. When would each be most and least effective for a research and development company dependent on employee innovation?

> What would you do during a corporate restructuring to ensure that your best employees did not leave?

> What type of person would be a good fit with Nordstrom’s extremely organic and informal structure? Why?

> If you wanted employees to work collaboratively and minimize conflict, what organizational structures would you consider adopting? Why? Which structures would you avoid? Why?

> What areas of an organization (e.g., what functions) do you think are the best to centralize? Which are the best to decentralize?

> Why do you think companies are moving toward flatter, more organic structures? Do you think this is appropriate?

> How do you think your career path might differ in a hierarchical versus a flat organization?

> Are office politics bad? Why or why not?