An engineer wishes to replace a 2.00 m wire with a 35.0 cm wire and use a 11.0 V supply instead of 34.0 V supply. In order to ensure the same resistive power from the new shorter wire operating with less voltage, what fractional change in a) resistivty, b) or radius would be necessary? I know the answers for part a) is 0.598 and part b) is 1.29 but how would I get that? Please help!!

An engineer wishes to replace a 2.00 m wire with a 35.0 cm wire and use a 11.0 V supply instead of 34.0 V supply. In order to ensure the same resistive power from the new shorter wire operating with less voltage, what fractional change in a) resistivty, b) or radius would be necessary? I know the answers for part a) is 0.598 and part b) is 1.29 but how would I get that? Please help!!

Physics for Scientists and Engineers: Foundations and Connections

1st Edition

ISBN:9781133939146

Author:Katz, Debora M.

Publisher:Katz, Debora M.

Chapter28: Current And Resistance

Section: Chapter Questions

Problem 57PQ

See similar textbooks

Similar questions

A 20.00-V battery is used to supply current to a 10-k resistor. Assume the voltage drop across any wires used for connections is negligible, (a) What is the current through the resistor? (b) What is the power dissipated by the resistor? (c) What is the power input from the battery; assuming all the electrical power is dissipated by the resistor? (d) What happens to the energy dissipated by the resistor?
Consider a cylindrical ohmic wire with the following dimensions: length = 10.0 m, radius = 0.05 m. When the ends of the wire were connected to a 2.0 V voltage source, a 1.0 A current through the wire was measured. Determine the resistivity of the wire. Choices: 3.93 x10^-4 Ω-m, 1.57 x 10^-3 Ω-m, 3.14 x 10^-2 Ω-m, 3.92 x 10^-2 Ω-m, 1.57 x 10^-1 Ω-m
Two resistors of resistance 230 O and 340 O are connected in series (one after the other). A potential difference of 20 V is applied between the ends of the chain. a)What is the total resistance of the circuit (in O)? Give your answer as a whole number. b)Calculate the current flowing through the circuit (in A). Gve your answer to 3 d.p. and use this value to that degree of accuracy, in subsequent calculations, if needed. c)Calculate the potential difference across the 230 O resistance. Give your answer in volts to 2 d.p..
What is the resistance (in units of 2) of a wire made of a material with a resistivity of 3.2 x 10-8.m, if its length is 49.1 m and its diameter is 0.50 mm? Solect ono:
What is the maximum power deliverable by a stack of 100 10YSZ cells to an optimum resistive load? Given each cell has open circuit voltage of 1.1V in series and the resistance is 17.78 ohms. The dimensions of the 10YSZ electrolyte are 0.1m x 0.1m x .0002m.
A (20.1 +/-0.2) ohms resistor is connected in parallel with a (39.9 +/- 0.4) ohm resistor. THe resistors are connected to a (2.90+/-0.3)V battery. a) Find the equivalent resistance (including uncertainty). b) Calculate the toal current in the circuilt (including uncertainty) c) Determine the value of the current in each branche of the circuit (including uncertainty). A image is included to the question.
A copper wire has a diameter 4.75 mm and resistivity 1.6 x 10-8 Ωm. What will be the length of this wire to make a resistance of 20Ω. What will be the new resistance, if the radius is doubled?
Suppose you're using a copper wire that has a radius of 0.5 mm, is 3.8 m long, and has a resistivity p=1.7 x 10 8 N- m. What is the resistance of the wire in Ohms?
A 9 V battery costs $1.49, and will run a portable CD player for 6 hours. Suppose the battery supplies a current of 25 mA to the player. What is the cost of the energy in dollars per kWh?
A solar cell generates a potential difference of 0.17 V when a 520 0 resistor is connected across it, and a potential difference of 0.25 V when a 940 resistor is substituted. What are the (a) internal resistance and (b) emf of the solar cell? (c) The area of the cell is 2.5 cm? and the rate per unit area at which it receives energy from light is 5.1 mW/cm². What is the efficiency of the cell for converting light energy to thermal energy in the 940 Q external resistor? (a) Number i Units (b) Number i Units (c) Number Units > >
An extension cord has a resistivity of p = 7.5 x 10-8 Ω.m. The cord is made from copper wire with a diameter D = 0.45 cm and it is L = 9.9 m long. (a) What is the resistance in ohms? R = (b) If a current of I= 2.95 A passes through the wire what voltage is the cord connected to, in volts? V=
A 660-N resistor is connected to a variable-voltage power supply. (a) What voltage is necessary to cause a current of 0.7 A in the resistor? V.