ELECTRICITY FOR TRADES
3rd Edition
ISBN: 9780078118630
Author: Petruzella
Publisher: RENT MCG
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 7.2, Problem 17RQ
The cold resistance of a tungsten lamp filament is measured using an ohmmeter and found to be much lower than the hot resistance calculated using Ohm’s law and the measured voltage and current values. How can this be possible?
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Can you please help me with this problem?
Consider the following transformer circuit assuming an ideal transformer. In this circuit
the signal generator will provide a 10-Volt peak-to-peak sinusoidal signal at a frequency
of 1.0 kHz. Assume that L₁ = 0.65 H, L2 = 0.00492 H (=4.92 mH) and that the coupling
constant = 0.99925.
+
VG1(
R1 1k
N1:N2
11.5:1
12
V1 N1
N2
V2
R2 8.2
1) Find the following using the theory presented in the prelab reading:
a) Start with Equations (2) of the prelab reading and show that the input impedance
to an ideal transformer is given by the equation for Z1 (=V1/11) in Equations (4) of
the prelab reading.
Equations (2) are: V₁ = joLI₁ + jœMI₂ and V₂ = j@MI₁ +j@L₂I₂
The equation for the input impedance is: Z₁ = 1½ = jwL₁ +
(WM)²
jwL₂+ZL
b) Assuming that Z is a real impedance, find the equations for the real and
imaginary parts of Z1.
c) Use your equations from part (b) to calculate the value of the input impedance
(Z) at an operating frequency of 200 Hz. Assume that the load impedance is 8.2
Ohms…
Use: R1 = 1.5K, R2 = 5K, R3 = 1K, R4 = 2K, R5 = 2K, R6 = 1K.
40%: Find the value for Vs (in V) such as IR2 = 1mA.
40%: Find the voltage VD.
20%: simulate the circuit in Falstad (attach the link).
A
1,5k
B
R1
Vs
L
5k
P2
R2
R6
E
C
R3
С
IR2= 1mA
D
H4
R4
2k
2k
R5
Chapter 7 Solutions
ELECTRICITY FOR TRADES
Ch. 7.1 - What is the base unit and symbol used for...Ch. 7.1 - Write the metric prefix and symbol used to...Ch. 7.1 - Convert each of the following: a. 2,500 to...Ch. 7.2 - State Ohms law.Ch. 7.2 - List the three formulas associated with Ohms law.Ch. 7.2 - Calculate the unknown value for each circuit (a)...Ch. 7.2 - A pilot lamp with 12 volts applied to it draws a...Ch. 7.2 - A resistor has a resistance of 220 . The current...Ch. 7.2 - An electric soldering iron with a 40- heating...Ch. 7.2 - A baseboard heater draws a current of 8 A when...
Ch. 7.2 - A sensor module has an internal resistance of...Ch. 7.2 - The current through and the voltage drop across a...Ch. 7.2 - The heating element for an electric floor heating...Ch. 7.2 - How much power is lost in the form of heat when 25...Ch. 7.2 - The voltage drop across a 330- resistor is...Ch. 7.2 - A digital multimeter display indicates a reading...Ch. 7.2 - Calculate the unknown value for each circuit (a)...Ch. 7.2 - Assume that applying 120 volts to a resistive load...Ch. 7.2 - The voltage drop across a 10-W, 330- resistor is...Ch. 7.2 - The cold resistance of a tungsten lamp filament is...Ch. 7.2 - An electric baseboard heater is rated for 1200 W...Ch. 7.2 - A lamp dimmer switch is rated for 5 A at 120 V....Ch. 7.2 - A 400-W 4- public address speaker is to be fused...
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, electrical-engineering and related others by exploring similar questions and additional content below.Similar questions
- The joint pdf of random variables X=1, 2 and Y=1,2,3 is Y P(X,Y)= X [0.105 0.2 0.15] 0.151 0.18arrow_forwardFind the eigenvalues and the corresponding eigen vectors of the following matrix: -5 A = [ 21 -7 4]arrow_forward+ 2) Acircuit is given as shown. (a) Find and label the circuit nodes (6) Determine voltages V₁, V2, V3 and Vy 4V C/E 노동 + 051 V4 + C/E + 3V- + /E5V 1 av + C E uk لا + V3C/E CIE + E6V -arrow_forward
- Consider the following transformer circuit assuming an ideal transformer. In this circuit the signal generator will provide a 10-Volt peak-to-peak sinusoidal signal at a frequency of 1.0 kHz. Assume that L₁ = 0.65 H, L2 = 0.00492 H (=4.92 mH) and that the coupling constant = 0.99925. + VG1( R1 1k N1:N2 11.5:1 12 V1 N1 N2 V2 R2 8.2 1) Find the following using the theory presented in the prelab reading: a) Start with Equations (2) of the prelab reading and show that the input impedance to an ideal transformer is given by the equation for Z1 (=V1/11) in Equations (4) of the prelab reading. Equations (2) are: V₁ = joLI₁ + jœMI₂ and V₂ = j@MI₁ +j@L₂I₂ The equation for the input impedance is: Z₁ = 1½ = jwL₁ + (WM)² jwL₂+ZL b) Assuming that Z is a real impedance, find the equations for the real and imaginary parts of Z1. c) Use your equations from part (b) to calculate the value of the input impedance (Z) at an operating frequency of 200 Hz. Assume that the load impedance is 8.2 Ohms…arrow_forwardHANDWRITTEN SOLUTION PLEASE NOT USING AIarrow_forwardFor the network of Fig. 7.93, determine: a. ID, and VGS₂- 18 V b. Vps and Vs. Shockley's equation, VGS ID= Vp) ID Vos V 1- VIDSS VGSQ VG = R₂VDD R₁ + R2 VGS VG-IDRS VDS VDD-ID(RD + Rs) (a) ID = 9 mA, VGS₁ = 0.5 V (b) VDs = 7.69 V, Vs = -0.5 V • 2.2 ΚΩ Dss = 8 mA Vp=-8V • 0.39 ΚΩ 8-4 V FIG. 7.93arrow_forward
- 4-9 A separate excited dc generator turning at 1400 r/min produces an induced voltage of 127 V. The armature resistance is 2 and the machine delivers a current of 12 A. Calculate a. the terminal voltage [V] b. the heat dissipated in the armature [W] c. the braking torque exerted by the armature [N-m]arrow_forward1. Label the x, y, z coordinates for each frame. 2. Compute the homogeneous transformation matrices H between frames 0, 1, 2, and end- effector. 3. Use your MATLAB function to compute H°3. 01 d₁ d 02 d3arrow_forward4-8 Explain the difference between shunt, com- pound, and differential compound generators a. as to construction b. as to electrical propertiesarrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Electricity for Refrigeration, Heating, and Air C...Mechanical EngineeringISBN:9781337399128Author:Russell E. SmithPublisher:Cengage Learning
Electricity for Refrigeration, Heating, and Air C...
Mechanical Engineering
ISBN:9781337399128
Author:Russell E. Smith
Publisher:Cengage Learning
What is an electric furnace and how does it work?; Author: Fire & Ice Heating and Air Conditioning Inc;https://www.youtube.com/watch?v=wjAWecPGi0M;License: Standard Youtube License