# Test5Review.pdf - PHYSICS 102 EAST LA COLLEGE TEST#5...

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PHYSICS 102, EAST LA COLLEGE TEST #5 Review (Ch 25 – 26) Mr. V. Kiledjian 1) A wire with a radius R = .89 mm and length 45 cm is made of two materials, Carbon and Nichrome. The Carbon portion is 15 cm long. The temperature of the wire is 75 oC. The wire is connected to a 12 volt battery. a) Find the total Resistance of the batteryb) Find the current (I) and the current density (J) and the electric field (E) in the wire.c) Find the power dissipated in the wire (P) and the power delivered by the battery.d) At what temperature is the total resistance of the wire 1 ohm less than at 20 Celsius?2) A Copper wire has a shape given by a radius that increases as R(x)= aex+ b. Its initial radius is .45 mm and final radius is 9.67 mm and its horizontal length is 38 cm. Find its resistance. 3) A battery with an Emf of 12 volts is hooked up to a 125 ohm resistor and an ammeter. The ammeter measures a current of 75 mA. a) Calculate the internal resistance of the battery and the actual voltage across the battery.b) Calculate the power dissipated in the resistor and the power generated by the battery.
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