Which of the following is false? O Batteries produce direct current alone. O The current reaching our homes is called AC. O Majority of our home appliances work on a 110-V line. AC is called alternating current because it changes directions many times each second. In an electrical circuit, electrons come from O a dry cell, wet cell or battery O the power station generator O the electrical conductor itself O the back emf of motors

Which of the following is false? O Batteries produce direct current alone. O The current reaching our homes is called AC. O Majority of our home appliances work on a 110-V line. AC is called alternating current because it changes directions many times each second. In an electrical circuit, electrons come from O a dry cell, wet cell or battery O the power station generator O the electrical conductor itself O the back emf of motors

University Physics Volume 2

18th Edition

ISBN:9781938168161

Author:OpenStax

Publisher:OpenStax

Chapter15: Alternating-current Circuits

Section: Chapter Questions

Problem 48P: A transformer is used to supply a 12-V model train with power from a 110-V wall plug. The train...

See similar textbooks

Similar questions

Check Your Understanding A transformer steps the line voltage down from 110 to 9.0 V so that a current of 0.50 A can be delivered to a doorbell (a) What is the ratio of the number of turns in the primary and secondary windings? (b) What is the current in the primary winding? (c) What is the resistance seen by the 110-V source?
(a) What is the voltage output of a transformer used for rechargeable flashlight batteries, if its primary has 500 turns, its secondary 4 turns, and the input voltage is 120 V? (b) What input current is required to produce a 4.00 A output? (c) What is the power input?
(a) What is the resistance of a 220-V AC short circuit that generates a peak power of 96.8 kW? (b) What would the average power be if the average power be if the voltage was 120 V AC?
An AC appliance cord has its hot and neutral wires separated by 3.00 mm and carries a 5.00-A current. (a) What is the average force per meter between the wires in the cord? (b) What is the maximum force per meter between the wires? (c) Are the forces attractive or repulsive? (d) Do appliance cords need any special design features to compensate for these forces?
A transformer is used to supply a 12-V model train with power from a 110-V wall plug. The train operates at 50 W of power, (a) What is the rms current in the secondary coil of the transformer? (b) What is me rms current in the primary coil? (c) What is the ratio of the number of primary to secondary turns? (d) What is the resistance of the tram? (e) What is the resistance seen by the 110-V source?
(a) What is the resistance of a 220-V ac short circuit that generates a peak power of 96.8 kW? (b) What would the average power be if the voltage were 120 V ac?
A young man owns a canister vacuum cleaner marked 535 W [at] 120 V and a Volkswagen Beetle, which he wishes to clean. He parks the car in his apartment parking lot and uses an inexpensive extension cord 15.0 m long to plug in the vacuum cleaner. You may assume the cleaner has constant resistance, (a) If the resistance of each of the two conductors in the extension cord is 0.900 , what is the actual power delivered to the cleaner? (b) If instead the power is to be at least 525 W, what must be the diameter of each of two identical copper conductors in the cord he buys? (c) Repeat part (b) assuming the power is to be at least 532 W.
Unreasonable Results An inventor wants to generate 120V power by moving a 1.00mlong wire perpendicular to the Earth’s 5.00105T field. (a) Find the speed with which the wire must move. (b) What is unreasonable about this result? (c) Which assumption is responsible?
A step-up transformer is designed so that the output of its secondary winding is 2000 V(rms) when the primary winding is connected to a 110-V (rms) line voltage, (a) If there are 100 turns in the primary winding, how many turns are there in the secondary winding? (b) If a resistor connected across the secondary winding draws an rms current of 0.75 A. what is the current in die primary winding?
(a) How much power is dissipated in a short circuit of 240-V ac through a resistance of 0.250 ? (b) What current flows?
In this problem, you will verify statements made at the end of the power losses for Example 20.10. (a) What current is needed to transmit 100 MW of power at a voltage of 25.0 kV? (b) Find the power loss in a 1.00 transmission line. (c) What percent loss does this represent?
In this chapter, most examples and problems involved direct current (DC). DC circuits have the current flowing in one direction, from positive to negative. When the current was changing, it was changed linearly from I=ImaxtoI=+Imax and the voltage changed linearly from V=Vmax to V=+Vmax where Vmax=ImaxR .Suppose a voltage source is placed in series with a resistor of R = 10 that supplied a current that alternated as a sine wave, for example, I(t)=(3.00A)sin(24.00st) . (a) What would a graph of the voltage drop across the resistor V(t) versus time look like? (b) What would a plot of V(t) versus I(t) for one period look like? (Hint: If you are not sure, try plotting V(t) versus I(t) using a spreadsheet.)