A battery having an emf (ɛ) of 12V provides a current of 85mA when connected to a load of 1250. i) Calculate the internal resistance (r) of the battery ( in Ω) ii) Calculate the terminal voltage (V) of the battery (in Volts)

A battery having an emf (ɛ) of 12V provides a current of 85mA when connected to a load of 1250. i) Calculate the internal resistance (r) of the battery ( in Ω) ii) Calculate the terminal voltage (V) of the battery (in Volts)

College Physics

1st Edition

ISBN:9781938168000

Author:Paul Peter Urone, Roger Hinrichs

Publisher:Paul Peter Urone, Roger Hinrichs

Chapter21: Circuits And Dc Instruments

Section: Chapter Questions

Problem 79PE: Construe! Your Own Problem Consider a rechargeable lithium cell that is to be used to power a...

See similar textbooks

Similar questions

A 240-kV power transmission line carrying 5.00x102. A is hung from grounded metal towers by ceramic insulators, each having a 1.00x 109- resistance. Figure 21.51. (a) What is the resistance to ground of 100 of these insulators? (b) Calculate the power dissipated by 100 of them, (c) What fraction of the power carried by the line is this? Explicitly show how you follow the steps in the Problem-Solving Strategies for Series and Parallel Resistors.
An automobile starter motor has an equivalent resistance of 0.0500 and is supplied by a 12.0-V battery with a 0.0100- internal resistance, (a) What is the current to the motor? (b) What voltage is applied to it? (c) What power is supplied to the motor? (d) Repeat these calculations for when the battery connections are corroded and add 0.0900 to the circuit. (Significant problems are caused by even small amounts of unwanted resistance in low-voltage, high-current applications.)
(a) F ind the voltage drop in an extension cord having a 0.0600-O resistance and through which 5.00 A is flowing. (b) A cheaper cord utilizes thinner wire and has a resistance of 0.300 O. What is the voltage drop in it when 5.00 A flows? (c) Why is the voltage to whatever appliance is being used reduced by this amount? What is the effect on the appliance?
You have a faculty position at a community college and are m (caching a class in automotive technology. You are deep in a discussion of using jumper cables to start a car with a dead battery from a car with a fresh battery. You have drawn the circuit diagram in Figure P27.16 to explain the process. The battery on the left is the live batten- in the correctly functioning car, with emf and internal resistance RL where the L. subscript refers to live. Its terminals are connected directly across those of the dead battery, in the middle of the diagram, with emf and internal resistance RD where the D subscript refers to "dead Then, the starter in the car with the dead battery is activated by closing the ignition switch, allowing the car to start. The resistance of the starter is Rs. A student raises his hand and asks, So is the dead battery being charged while the starter is operating? How do you respond?
The label on a battery-powered radio recommends the use of a rechargeable nickel-cadmium cell (nicads), although it has a 1.25-V emf, whereas an alkaline cell has a 1.58-V emf. The radio has a 3.20 resistance.(a) Draw a circuit diagram of the radio and its battery. Now, calculate the power delivered to the radio (b) when using a nicad cells, each having an internal resistance of 0.0400 , and (c) when using an alkaline cell, having an internal resistance of 0.200 . (d) Does this differenceseem significant, considering that the radio's effective resistance is lowered when its volume is aimed up?
Consider the circuit shown in Figure P18.10. (a) Calculate the equivalent resistance of the 10.0- and 5.00- resistors connected in parallel. (b) Using the result of part (a), calculate the combined resistance of the 10.0-, 5.00-, and 4.00- resistors. (c) Calculate the equivalent resistance of the combined resistance found in part (b) and the parallel 3.00- resistor. (d) Combine the equivalent resistance found in part (c) with the 2.00- resistor. (e) Calculate the total current in the circuit. (f) What is the voltage drop across the 2.00- resistor? (g) Subtracting the result of part (f) from the battery voltage, find the voltage across the 3.00- resistor. (h) Calculate the current in the 3.00- resistor. Figure P18.10
Suppose you measure the terminal voltage of a 3.2G0-V lithium cell having an internal resistance of 5.00 by placing a 1.00-k voltmeter across its terminals, (a) What current flows? (b) Find the terminal voltage, (c) To see how close the measured terminal voltage is to the emf, calculate their ratio.
Construe! Your Own Problem Consider a rechargeable lithium cell that is to be used to power a camcorder. Construct a problem in which you calculate the internal resistance of the cell during normal operation. Also, calculate the minimum voltage output of a battery charger to be used to recharge your lithium cell. Among the things to be considered are the emf and useful terminal voltage of a lithium cell and the current it should be able to supply to a camcorder.
A car battery with a 12-V emf and an internal resistance of 0.050 is being charged with a current of 60 A. Note that in this process the battery is being charged. (a) What is the potential difference across its terminals? (b) At what rate is thermal energy being dissipated in the battery? (c) At what rate is electric energy being converted to chemical energy? (d) What are the answers to (a) and (b) when the battery is used to supply 60 A to the starter motor?
Integrated Concepts A flashing lamp in a Christmas earring is based on an RC discharge of a capacitor through its resistance. The effective duration of the flash is 0.250 s, during which it produces in average 0.500 W from an average 3.00 V. (a) What energy does it dissipate? (b) How much charge moves through the lamp? (c) Find the capacitance. (d) What is the resistance of the lamp?
Integrated Concepts (a) An immersion heater utilizing 120 V can raise the temperature of a 1.00 102 -g aluminum cup containing 350 g of water from 20.0°C to 95.0°C in 2.00 min. Find its resistance, assuming it is constant during the process. (b) A lower resistance would shorten the heating time. Discuss the practical limits to speeding the heating by lowering the resistance.
A person with body resistance between his hands of 1.00 k accidentally grasps the terminals of a 20.0-kV power supply. (Do NOT do this!) (a) Draw a circuit diagram to represent the situation. (b) If the internal resistance of the power supply is 2000 , what is the current through his body? (c) What is the power dissipated in his body? (d) If the power supply is to be made safe by increasing its internal resistance, what should the internal resistance be for the maximum current in this situation to be 1.00 mA or less? (e) Will this modification compromise the effectiveness of the power supply for driving low-re si stance devices? Explain your reasoning,