Exam 2 MU Spring 2022 PHY 102 Last Name First Name Printed Printed ID Signature Recitation TA Claudio Barros Dylan Delgado Nitin Kumar Kunal Mozumdar Jiayang Xiao Yue Xing Recitation Day Time You are allowed a calculator and ONE 8 5 x11 sheet of paper with whatever you wish written on it both sides answers must have the right units You must show ALL your work to receive full credit for regular problems Numerical Use the back of the problem page if you need more space and mark OVER on the front to indicate that there is material on the back side For the multiple choice questions clearly write the letter of your choice on the front page No points will be given if two or more choices are circled Answers to Multiple Choice Questions Please write your answers clearly here 2 8 3 9 4 10 5 11 6 12 1 7 Please note that giving or receiving aid on an exam or any act of academic dishonesty is cause for dismissal from the University Question Score Grader 1 12 13 14 15 16 TOTAL USEFUL CONSTANTS m s2 8 99 109 N m2 0 1 257 10 6 9 8 1 602 10 19 C 9 11 10 31 kg 1 67 10 27 kg 3 00 108 m s 6 63 10 34 J s 4 14 10 15 eV s C2 0 8 85 10 12 F m T m A Multiple Choice Questions You do not need to show your work Please write down the answer on the front page No partial credit will be given 3 points each 1 SLI LO2 Which of the following methods provides the most conclusive evidence of an effect by one factor called the independent variable on another called the dependent variable 2 SLI LO4 If a solar panel can harness about 20 of the 1250 W of solar energy striking each square meter of the Earth s surface what area of solar panels would be required to provide 2000 W of power for a house during daylight hours 3 SLI LO6 Which statement regarding the radio waves and other low frequency EM radiation routinely encountered by people is most accurate a Radio waves cause headaches b Radio waves have been shown to increase cancer risk in children c Radio waves have no known mechanism of causing harm to people d Radio waves cause dangerous heating of the skin 4 A charged particle is moving in a uniform magnetic field Which of the following paths are a Personal Anecdote b Personal Conviction c Correlational Research d Controlled Experiment a 3 0 m2 b 5 0 m2 c 8 0 m2 d 12 m2 possible for it to follow a A Circular Path b A Helical Path c A Straight Line d Each of the above is possible a 0 b 15 c 30 d 45 direct current a 2 7 T b 3 1 T c 3 6 T d 4 4 T 5 What is the angle between a single 640 cm2 wire loop carrying 1 0 A of current and a 2 0 T magnetic field exerting a torque of 0 090 N m of torque on it 6 How strong is the magnetic field at the center of a 1 4 m radius ring of wire carrying 7 0 A of 7 A flat coil of wire consisting of 4 turns each with an area of 200 cm2 is positioned perpendicularly to a uniform magnetic field that increases its magnitude at a constant rate from 10 mT to 25 mT in 5 0 ms If the coil has a total resistance of 5 0 what is the magnitude of the induced current 8 An emf of 0 40 V is measured across an inductor at the current increases by 0 50 A s What is the inductance of the inductor 9 If the rms current provided by an AC source is 10 A what is the max current it is providing 10 An ideal transformer steps up the voltage of a 50 A 1800 V rms generator to 100 000 V What is the new current 11 What is the energy of a photon of light with a frequency of 6 25 1014 Hz 12 What is refraction a The separation of wavelengths of light due to differences in the index of refraction b The bending of light upon entering a new medium c The bouncing of light off a surface at the same angle as that of incidence d The shortening of wavelengths of light inside a non vacuum medium a 60 mA b 48 mA c 12 mA d 0 24 mA a 0 20 H b 0 40 H c 0 60 H d 0 80 H a 10 A b 14 A c 18 A d 20 A a 0 90 A b 1 8 A c 1400 A d 2800 A a 1 62 eV b 1 94 eV c 2 58 eV d 3 27 eV Problems You MUST show ALL your work and use correct units for numerical answers to receive full credit 13 A proton and an electron move toward the right in a 5 0 T magnetic field B pointing into the page as shown in the diagram The velocity of each is 2 0 105 m s a Find the magnitude and direction of the magnetic force acting on the proton 4 points b Find the magnitude and direction of the magnetic force acting on the electron 4 points c Find the radius of the electron s orbit 4 points d Find the time for the electron to complete one circular orbit 4 points 14 A 50 turn rectangular coil width 20 cm length 30 cm rotates about an axis at 60 rad s in a uniform horizontal magnetic field as shown in the figure The magnetic field is 0 25 T and the resistance of the coil is 1 5 a What are the maximum and minimum magnetic fluxes through the coil 4 points b What are the maximum induced emf and the maximum electrical power consumed by the coil 4 points c If the emf is 0 at t 0 what is the emf at t 0 5 s 4 points d What is the maximum torque experienced by the coil from the magnetic field 4 points 15 An RLC circuit contains a 148 resistor 1 5 F capacitor and an unknown inductor connected in series with a generator with an rms voltage of 35 V a If the capacitive reactance of the circuit is 207 2 what is the frequency of the current 4 points b If the circuit is in resonance at this frequency what is the inductance 4 points c Calculate the total impedance and rms current in the circuit at resonance 4 points d Calculate the rms voltage across the inductor 4 points 16 The figure shows the path of a ray of light through several layers thickness 2 cm each with different indices of refraction a If the angle of incidence 1 at the first interface is 30o find …