=29 B=39 0:139 D=12 Will be graded: l. The gure shows cross sections through three long conductors ofthe same length and the same material, with square cross sections of edge lengths as shown. Conductor B ts snugly within conductor A, and conductor C ts snugly within conductor B. a. Calculate the cross-sectional area of each conductor in terms of L'.' (IS points) b. Rank the cross-sectional areas of A, B, and C? (I5 points) c. Rank the resistance ofA. B. and C? Explain how? (20 points) Don C 2. Find the current i ofthe circuit? (25 points) III Do [or practice and earn {25 points! (or certication: 3. Two wires. 0 and b. are made of the same metal and have equal length, but the resistance of wire a is D Q the resistance of wire I) is B Q. How do their diameters compare? 4. When a potential difference is applied to a certain copper wire. a current of DES A passes through the wire. Ifthe wire was removed from the circuit and replaced with a copper wire of twice the cross-sectional area, what current would ow through the new wire? Assume the wires are identical in all other aspects. Dr. Hetti l PHY 116 5. Suppose at BC the resistance of a platinum resistance thermometer is C Q. When placed in a particular solution. the resistance is D+l00 Q. What is the temperature of this solution? Temperature Coefficient of resistivity for platinum is 3.93 x 10" 1/\"C. 6. A voltage D V is applied to a device of resistance R; and the current through the device is i. lt'the device obeys Ohm's law. what will be the outcome if the voltage is increased to 20 V? 7. Two identical resistors are connected in series across the terminals ofa battery with a voltage V and a current I flow through the circuit. If one of the resistors is removed from the circuit and the remaining one connected across the terminals of the battery, how much current would flow through the circuit? 8. Two lightbulbs operate at 120 V. but one has a power rating of 25 W while the other has a power rating of 100 W. Which one has the greater resistance? What is the value of the peak voltage if you use 120 V AC power? What is the peak power consumption rate of the 25 W AC light bulb