Exam 2 Spring 2024 PHY 102 Last Name Printed Recitation TA Sangit Baskota Xi Chen Magdy Elshahawy Shang Jie Liou Pooja Shrestha Pranjal Srivastava Recitation Day Time First Name Printed 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 9 8 1 602 10 19 C 9 11 10 31 kg 1 67 10 27 kg C2 0 8 85 10 12 F 0 1 257 10 6 T m A m 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 If there is a magnetic force acting on a classical particle it is possible that the particle is 2 The magnetic force exerted on a current carrying wire by an external magnetic field is NOT A Neutral carrying no charge B Standing still C Moving parallel to the magnetic field D Moving perpendicular to the magnetic field proportional to which of the following A The amount of current B The length of the current carrying wire C The strength of the magnetic field D The cross sectional area of the current carrying wire 3 In a mass spectrometer charged ions make circular motions under a magnetic field Those circular path will have a smaller radius if A The speed is greater B The charge is greater C The mass is greater D The magnetic field is weaker 4 Which of the following changes would NOT cause a current to flow through a loop of wire entirely inside a uniform magnetic field with magnetic field lines directed through it A Accelerating the loop in a direction perpendicular to magnetic field B Increasing the strength of the magnetic field C Reducing the size of the loop D Flipping the loop over 5 A flat 200 turn coil of wire with an area of 300 cm2 is within a 30 mT magnetic field At what frequency must it be rotated to generate an AC voltage with an amplitude of 8 0 V 6 An RL circuit has R 0 30 L 450 mH a switch and a 9 0 V battery How long after the switch is closed does the current reach 1 0 A A 0 03 Hz B 2 9 Hz C 7 1 Hz D 8 4 Hz A 51 ms B 180 ms C 1 8 s D 5 1 s 7 If the driving frequency of an RLC circuit is increased by a factor of three which of the following must happen A Resistance will increase by 3 times B Inductive reactance will increase by 3 times C Capacitive reactance will increase by 3 times D The circuit s impedance will increase by 3 times 8 Which of the following is NOT correct regarding the resonance in an RLC circuit A One can obtain resonance by tuning the frequency of the AC circuit B One can obtain resonance by changing the resistance of a resistor C One can obtain resonance by changing the capacitance of a capacitor D One can obtain resonance by adjusting the inductance of an inductor 9 A transformer consists of a 500 turn primary coil and a 2000 turn secondary coil If the current in the secondary is 3 00 A what is the current flowing in the primary coil 10 As the angle of incidence of a light ray on a flat mirror is increased toward its maximum value what value does the sum of the incident and reflected angles become 11 A ray of light in a liquid is incident on a liquid to glass interface at an angle of 35 The indices of refraction for the liquid and glass are 1 63 and 1 52 respectively What is the angle of refraction for the ray moving through the glass 12 The formation of rainbow is NOT caused by which of the following mechanisms A The refractive index is the same for all colors B Water droplets being colorful C Reflection of light D Sunlight is composed of light of different frequencies colors A 0 75A B 1 33 A C 12 A D 48 A A 45 B 90 C 180 D 360 A 23 B 34 C 38 D 42 Problems You MUST show ALL your work and use correct units for numerical answers to receive full credit 13 A pair of long horizontal wires are separated by 0 25 m The top wire carries a current 1 3 0 A toward the right while the bottom wire carries a current 2 2 0 A toward the left Point is a distance 0 25 m above the top wire a What is the symbolic equation for computing the strength of the magnetic field a distance from a long straight wire carrying current 3 points b What is the magnitude of the magnetic field at point 2 point c What is the direction of the magnetic field at point 3 points d What is the magnitude of the magnetic force per unit length exerted on the bottom wire 5 points e What is the direction of the magnetic force exerted on the bottom wire 3 points 14 Consider the conducting bar with negligible resistance sliding to the right along two wires as indicated in the figure Assume that R 18 0 that the length of the moving bar is 120 cm and that a uniform 2 50 T magnetic field is directed into the page The bar is moving with a constant velocity v and the induced emf is 9 V a Calculate how fast the bar is moving to the right 5 points b Calculate the current through the bar 3 points c Calculate the magnitude of the magnetic force acting on the moving bar with the current calculated in part b going through it 4 points d When the bar is 50 cm from the resistor what is the magnetic flux through the loop 4 points R v 15 An RLC circuit is connected to an AC source The known quantities are R 100 L 1 00 H C 1 50 F and Vmax 150 V a What is the resonance frequency for this circuit 3 points b Find the inductive reactance and …