Clicker questions. Clicker question 2. Clicker Question 1. Clicker question 2. Clicker question 1. the answers are in the lower right corner

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1 licker questions the answers are in the lower right corner question wave on a string goes rom a thin string to a thick string. What picture best represents the wave some time ater hitting the boundary? eore licker Question 1 tube open at both ends has a undamental requency o. I one end o the tube is closed the undamental requency o the tube will be.. licker question 2 string o length L ixed at both ends is vibrating at the requency o the second harmonic. There is a anti-node at a distance o rom the end.. 2. /2. 4. L/2. L/3. L/4. L/6 licker question 1 ire truck is approaching a ire with its siren on at requency and speed o 5 m/s. The observers at the ire hear a requency o =. v is the speed o sound =340 m/s v 5 ) + v ) 5 v v licker question 2 train is approaching a tunnel in a mountain with its whistle blowing with requency and speed 20 m/s. The sound relects o the mountain and is heard by an observer on the train with a requency o. v + 20 v 20 ) ) v 20 v 20 ) v ) v v + 5 v 5 ) v + 20 ) v + 20 v 20 v

2 licker question 3 The door in a microwave oven is glass with a metal screen and blocks microwaves rom escaping. The reason why you can see the ood but not eel the heat is that. ) Microwaves cannot pass through glass. ) The size on the holes in the screen are larger than the wavelength o light but smaller than the wavelength o microwaves. ) The microwaves are completely absorbed in the oven. ) The microwaves are directed only in the vertical direction. Question 1 For total internal relection at an interace the light. ) must have a small angle o incidence ) must go rom a higher to lower index o reraction. ) must go rom a lower to higher index o reraction. ) can go rom either a higher or lower index o reraction licker Question 1 boy stands 0.2 m in ront o a concave mirror with a ocal length o 0.5 m. His image will be. ) real and upright ) real and inverted ) virtual and upright ) virtual and inverted licker Question 2 boy stands 0.5 m rom a convex mirror with a radius o curvature o 1.0 m. The magniication will be between. ) 0 and 1.0 ) 1.0 and ininity ) 0 and 1.0 ) and ininity. licker question 3 candle is placed 30 cm in ront o a converging lens with a ocal length o 20 cm. The image will be and. ) Real, upright ) Real, inverted ) Virtual, upright ) Virtual, inverted licker question 4 candle is placed 15 cm in ront o a converging lens with a ocal length o 20 cm. The image will be and. ) Real, upright ) Real, inverted ) Virtual, upright ) Virtual, inverted 2

3 licker question 1 Where would an object be placed in ront o the converging lens below, in order to produce a real, enlarged image? licker question 2 camera lens ocuses the image an approaching runner onto a detector. s the runner gets closer the distance rom the lens to the detector. ) increases ) decreases ) remains the same licker question 3 question 4 Your eye ocuses on an approaching runner by changing its ocal length. s the runner approaches, the ocal length o the eye must. ) increase ) decrease ) remain the same You are a survivor on a desert island and want to make a ire by ocusing sunlight. You can use. ) a lat sheet o glass rom Josh. ) the eye glasses rom lex who is nearsighted. ) the eye glasses rom renda who is arsighted. ) the compact mirror rom Rhoda. licker question 1 For a compound microscope to have the highest angular magniication the ocal length o the objective lens must be and the ocal length o the eyepiece must be. licker question 2 For a reracting telescope to have the highest angular magniication, the ocal length o the objective lens must be and the ocal length o the eyepiece must be.. long, long. long, short. short, long. short, short. long, long. long, short. short, long. short, short 3

4 licker question 3 Suppose you have light going through two crossed polarizers. What will happen i a third polarizer is placed in between the two with polarization angle o 45 o? ) nothing will change ) the transmitted light will decrease ) the transmitted light will increase ) the transmitted light will go to zero licker Question 1 In a two slit intererence experiment, how does the separation between peaks in the intererence pattern change i the distance between slits is increased?. Increase. ecrease. Stays the same. Indeterminate licker Question 2 In a two slit intererence experiment how does the distance between the peaks on the screen change i the wavelength o the light is increased?. increases. decreases. stays the same. indeterminate licker question 3 1 λ 2 n For the Newton s ring pattern ormed by a lens the condition or the path dierence at the irst bright concentric ring is that 2t =. (t = the distance across the air gap, n = reractive index o glass) ) 1 λ ) 2 n ) λ ) n 1 2 λ λ licker question 1 licker question 2 diraction pattern is observed when a laser beam is passed through a small slit. I the slit width is made smaller the diraction patter will.. Not change. e wider. e narrower I light with a shorter wavelength is used in the single slit diraction experiment. The angle to the irst minimum will be. ) increased ) decreased ) remain the same ) uncertain 4

5 licker question 3 Laser light with a wavelength o 0.5 µm is passed through a slit with a width a= 0.5 mm (1000 times larger than λ).the irst minimum in the diraction pattern seen on a wall ar away will occur at an angle o about. ) 10-2 radian ) 10-3 radian ) 10-4 radian ) 10-5 radian licker question 4 laser beam is used to read the inormation on an optical disc. In order to get more inormation on the disc the wavelength o the laser should be.. Larger. Smaller. It doesn t matter. licker question 1 star in the sky appears to be blue. The temperature o this star must be. ) higher than that o the sun ) lower than that o the sun ) equal to that o the sun ) about that o the earth licker question 2 light emitting diode can be a more eicient light source than an incandescent lamp because. it is powered by electricity. it does not use black body radiation. it uses black body radiation. it has a high temperature licker question 3 Photons with λ=250 nm (5.0eV) hit a metal surace and emit photoelectrons with a maximum KE o 1.0 ev. What is the work unction o the metal? ) 1.0 ev ) 2.0 ev ) 3.0 ev ) 4.0 ev licker question 4 In a photoelectric eect experiment the ollowing data was obtained with two dierent metals. KE max Which metal has the larger work unction? ) ) 5

6 licker question 1 n electron with an energy o 1000 ev has a de roglie wavelength o 0.04 nm. I the speed o the electron is increased by 10 old the wavelength will be.. increased by a actor o 10. decreased by a actor o 1/10. increased by a actor o 10. decreased by a actor o 1/ 10 licker question 2 n electron with an energy o 1000 ev has a de roglie wavelength o 0.04 nm. I the energy is increased by 10 old the wavelength will be.. increased by a actor o 10. decreased by a actor o 1/10. decreased by a actor o 100. decreased by a actor o 1/ 10 licker question 1 In the ohr model o the hydrogen atom the lowest energy state o the electron has a circumerence equal to times the de roglie wavelength o the electron ) ½ ) 1 ) 2 ) n licker question 2 In the ohr model o the hydrogen atom the photon emitted in the transition rom the n=3 to n=1 state has an energy o times 13.6 ev (E o ) ) 3/9 ) 3/4 ) 8/9 ) 1 licker question 3 Suppose the rule or the orbital angular momentum quantum number is that l can have values rom 0 to n. (instead o n-1) The number o electrons in the n=1 shell would be licker question 4 The noble gas Kr has Z=36 and a outer electron coniguration o 3d 10, 4s 2, 4p 6. The next noble gas is Xe Z=54. The electrons to be added will be in the ollowing subshells.. 4d. 4d 5s. 4d 5s 5p. 4d 5s 5p 5d 6

7 licker Question 1 licker Question 2 Light rom an incandescent lamp is not like laser light because it is.. not monochromatic. not collimated. does not arise rom stimulated emission. all o the above The reason a laser beam is highly collimated is due to. ) a population inversion ) relection rom mirrors ) ocusing by lenses ) atomic excitations licker question 3 You are designing a diode laser with a shorter wavelength to read more inormation in a V. To do this you need to use a semiconductor.. with a larger band gap. with a smaller band gap. with a smaller size. with a larger size licker question 4 In order to have the highest eiciency, a solar cell should have a band gap. ) as large as possible ) as small as possible ) close to the average photon energy or sunlight ) with any size licker question 2 licker question 3 14 Suppose you had nuclei o 6 and wanted to release energy by orming an new nucleus. How could this be done?. by usion. by ission. by separation o protons and neutrons. it could not be done The amount o 14 in the atmosphere is relatively constant because it is generated by a nuclear reaction. When it is ixed by incorporation plant or animal material it decays with a hal lie o 5730 years. This can be used to determine the age o specimens. Suppose an ancient bone is ound in which the ratio o 14 /12 is 1/4 that ound in the atmosphere. bout how old is the bone?.3000 years.6000 years.9000 years years 7

8 licker question 4 Two light nuclei come together and use orming a larger nucleus. The mass o the product nucleus is less than the mass o the original nuclei. In this reaction. energy is released. energy is taken up. energy is unchanged 8