Lab 9 Worksheet

Explain the use of magnets and magnetism in tape recorders. -how tape recorders work? -what is the purpose of magnets in tape recorders? -What is the physics concept of magnetism?

.________ is a term used to describe a material's ability to retain magnetism. a) Coercive force b) Retentivity c) either "a" or "b" d) neither "a" nor "b" A coercive force is desirable in materials that is intended to be used as temporary magnets. a) low b) high c) extremely high d) any of the above A) Upon what does the electroniagnetic strength of an air-cored coil depend? a) number of turns in the coil b) amount of current flowing through the coil c) both "a" and "b" d) neither "a" nor "b" B) Upon what does the electromagnetic strength of an iron-cored coil depend? a) amount of current flow b) number of turns c) permeability of the core d) all of the above The left hand rule for a coil is such that if you were to hold a coil in your left hand with your fingers pointing in the direction of electron flow, your thumb would point in the direction of the a) electron flow b) lines of flux c) north pole face d) none of the above

In this Exercise 6 we will explore laws critical to the study of electromagnetism. We will be using Simulation 3 (below) to explore how a moving magnet produces current in a nearby coil of wire.   a. Magnetic field strength decreases as you get farther from the poles of the magnet. Does the flux through the face of the coil change as you move the magnet? Explain your answer. b. Why does the meter needle deflect? Is the deflection in accordance with Lenz’s Law? Justify your answer in terms of Lenz’s law and your above answers.

A bar magnet is divided in two pieces. Which of the following statements is true? a. The bar magnet is demagnetized. b. The magnetic field of each separated piece becomes stronger. c. The magnetic poles are separated. d. Two new bar magnets are created.

Answer the questions. 1. Formed when a wire in an electric circuit is wrapped around an iron core producing a magnetic field a) Electromagnet b) Generator c) Motor d) Bar Magnet 2. Produces an electric current when a coil of wire wrapped around an iron core is rotated near a magnet a) Car b) Generator c) Motor d) Magnet 3. Changes electrical energy to mechanical energy. a) Magnet b) Simple Electric Motor c) Generator d) Car In a simple electric motor, like poles of the magnets repel and unlike poles of the magnets attract. This causes the coil to rotate and thus changes electrical energy to energy a) Chemical b) Mechanical c) Sound d) Light 5. Surrounding a magnet is a that applies a force, a push or pull, without actually touching an object. a) Coil b) Magnetic Field c) Car d) Circuit

3. i. Write the working principle of Permanent Magnet Moving Coil instrument mention the importance spring used. ii. Explain how a single PMMC instrument can be used as ammeter and voltmeter.

QUESTION FIVE Figure 5 shows the cross section of Direct Current, mostly referred to as DC Machine. 1 2 NBA D 7 N S 3 5 8 Frame Figure 2 Cross Section of a DC machine Label All the numbered parts and define one of their respective function in the format as illustrated: Label 8: Frame Function: It completes a path of minimal reluctance to the magnetic field.

Answer question clearly and fully. Make sure I can properly read out the steps. Include any and all equations used during the solving process.

#28 The correct answer is already highlighted, explain in a very simple way why that is the correct answer. Briefly discuss its concept & provide an illustrative example.

Magnets are the main component in: Select one: capacitors. motors. permanent magnets. ohmmeters.

Fill in the correct answers. Two like poles within magnetic reach of each other The magnetic force on a bar magnet is strongest at the. they leave the pole. Magnetic lines have pole and enter the. Magnetic field may be also called The unit of magnetic field is or IWebber is the unit to measure and equal lines.

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Subject: Electric machines Please I need correct answer

The only question I need answered is at the bottom of the page: How would you explain the +/- readings of the digital weighing machine during the experiment?    If you would like to correct my answer to the question above this one, I would be very greatful but understand if you are unable to! thank you!

(a) A standard magnetic testing experiment using a ballistic galvanometer (BG) and reverse current method was conducted to determine the magnetic permeability of an iron ring sample. The parameters used in the experiment are listed in Table Q2(a) below. Table Q2(a) Value 150 turns Parameter The no. of turns of the magnetizing coil The no. of turns of the search coil 200 turns The BG constant 5 µC/scale division The internal resistance of the BG 150 2 2.5 cm2 The cross-sectional area of the ring sample The diameter of the ring sample The resistance of the search coil The resistance of the magnetizing coil 12 cm 10 2 7Ω (i) Determine the current needed to produce a magnetizing force of 10x10 A- turns/m. (ii) If the BG gives a throw of 70 scale division when the current is reversed, find the flux in the sample. (iii) Determine the relative permeability of the sample. (The permeability of free space, lo = 4n x 10-7H/m).

" MAGNETS AND MAGNETIC CIRCUIT " Please Refer To the Answer Key. Please indicate solution so that I could understand If I'm wrong with my solutions.  THANKYOU!

please explain step by step and show work   Please answer all subpart either dislike is ready please all subpart in clean handwriting please ASAP

please answe asap.. answer only. ADVANCED PHYSICS (THUMBS UP WILL BE GIVEN. PLEASE CHOOSE THE CORRECT ANSWER. NO LONG EXPLANATION NEEDED.)

Calculate the voltage of the DC source and the stored field energy of the actuator illustrated infigure 1.1. The dimensions of the magnetic circuit proposed in shown figure 1.2. The core of the magnetic circuit is made of cast steel material whose B-H characteristics is illustrated in figure 1.3. The coil in figure 1.1 has 250 turns, and the coil resistance is 5 ohms. For a given length g=5mm, a Dc source is connected to the coil to produce a flux density of 1 Tesla in the air gap.

the armature mmf can be -2 reduced by reluctance of the magnetic the circuit in the region of the pole .tip a) Increasing, O b) decreasing O c) don't put O

#35 The correct answer is already highlighted, explain in a very simple way why that is the correct answer. Briefly discuss its concept & provide an illustrative example.

#4. Please answer--What are the factors responsible for the execution of Spark?.

#37 The correct answer is already highlighted, explain in a very simple way why that is the correct answer. Briefly discuss its concept & provide an illustrative example.

The 'skin effecť is a phenomenon experienced when current flows through a metal. Which two of the following statements are correct? 15 Select one or more: O a. A smaller 'skin depth' implies a higher resistance O b. Direct current can cause the skin effect O c. The skin depth is smaller in highly conductive metals O d. The skin depth is larger in metals with high magnetic permeability

1) Choose the conductor which exerts a mechanical force, when placed in a magnetic field.   a. Neutral conductor b. Voltage Carrying Conductor c. Semi Conductor  d. Current Carrying Conductor Clear my choice

Select the correct answer for each of the following statements Book Source: Electricity 3 | 10th Edition ISBN-13:9781111646738 ISBN:1111646732 Authors:Jeffrey J. Keljik