Question: Measurements on a small permanent-magnet dc motor indicate that it has an armature resistance of 4.6. With an applied armature voltage of 5 V, the

Measurements on a small permanent-magnet dc motor indicate that it has an armature resistance of 4.6Ω. With an applied armature voltage of 5 V, the motor is observed to achieve a no-load speed of 11,210r/min while drawing an armature current of 12.5 mA.

a. Calculate the motor torque constant Km in V/(rad/sec).

b. Calculate the no-load rotational losses in mW. Assume the motor to be operating from an applied armature voltage of 5V.

c. Find the stall current and torque of the motor.

d. At what speeds will the motor achieve an output power of 1 W? Estimate the motor efficiency under these operating conditions. Assume that the rotational loss varies as the cube of the speed.

Step by Step Solution

★★★★★

3.34 Rating (175 Votes )

There are 3 Steps involved in it

1 Expert Approved Answer

Step: 1 Unlock

part a Va Iani Ra At no load wmnl 494 V Thus Km Eanl wmnl p... View full answer

Question Has Been Solved by an Expert!

Get step-by-step solutions from verified subject matter experts

Step: 2 Unlock

Step: 3 Unlock

Document Format (1 attachment)

20-E-E-E-M (218).docx

120 KBs Word File

Students Have Also Explored These Related Electrical Engineering Questions!

A motor has an armature resistance of 3.25 . If it draws 8.20 A when running at full speed and connected to a 120-V line, how large is the back emf?

A volleyball is spiked so that it has an initial velocity of 15 m/s directed downward at an angle of 550 below the horizontal. What is the horizontal component of the balls velocity when the opposing...

A motor has an armature resistance of 3.65. If it draws 8.20 A when running at full speed and connected to a 120-V line, how large is the back emf?

Statistics Questions:- The power rating of a motor can be modified to account for different ambient temperature, according to the following table: Ambient 30 35 C 40 C temperature C Variation of...

Please help me .. am stuck... please address all questions clearly:- The power rating of a motor can be modified to account for different ambient temperature, according to the following table:...

1.What is meant by Fayol's principle of'esprit de corps'? 2. Which principle of management implies that there should be 'one head and oneplan' for a group of activities having the same objective? 3....

TB0383 Andrew C. Inkpen General Electric's Corporate Strategy Like the premature obituary of writer Mark Twain, reports of the death of the conglomerate are often exaggerated. Diversified companies,...

Business Research MethodologyQuestion Bank 1 1. When the marketing department of an organization attempts to determine the amount of time the managers in this department spend at their computers in...

Business Research Methodology- Question Bank 1 1. When the marketing department of an organization attempts to determine the amount of time the managers in this department spend at their computers in...

10. An experimenter has some degree of control over the: a. independent variable. b. correlative variable. c. history effect. d. All of the above, if the experiment is conducted properly. 11. If a...

Consider the following problem. Maximize Z = 4x1 + 2x2 + 3x3 + 5x4, Subject to and xj 0, for j = 1, 2, 3, 4. (a) Using the Big M method, construct the complete first simplex tableau for the simplex...

A wooden cylinder of diameter 4r, height h and density p/3 is kept on a hole of diameter 2r of a tank, filled with water of density p as shown in the figure. The height of the base of cylinder from...

17.3 Distinguish between absorption costing and variable costing.

An aluminum pipe, 0.655 m long at 20.0C and open at both ends, is used as a flute. The pipe is cooled to a low temperature but then is filled with air at 20.0C as soon as you start to play it. After...

An aluminum cup of mass 200 g contains 800 g of water in thermal equilibrium at 80.0C. The combination of cup and water is cooled uniformly so that the temperature decreases by 1.50C per minute. At...

An aluminum calorimeter with a mass of 100 g contains 250 g of water. The calorimeter and water are in thermal equilibrium at 10.0C. Two metallic blocks are placed into the water. One is a 50.0-g...

Although the average speed of gas molecules in thermal equilibrium at some temperature is greater than zero, the average velocity is zero. Explain why this statement must be true.

An air rifle shoots a lead pellet by allowing high-pressure air to expand, propelling the pellet down the rifle barrel. Because this process happens very quickly, no appreciable thermal conduction...

Describe the operation of the circuit in Figure 8-42. Figures 8-42 OUTPUT SELECT 74HC04 (a) 74HC4016 10 10 k VIN OUTPUT SELECT X +5 V OV +5 V OV 5 V 5 V OV (b)

Consider a simply supported beam of rectangular cross section of constant width b and variable depth h, so proportioned that the maximum stress x at the outer surface due to bending is constant, when...

In Prob. 3-30, h →0 as x →0, which cannot occur. If the maximum shear stress τmax due to direct shear is to be constant in this region, show that the depth h at location x is given by 3...

Consider a simply supported static beam of circular cross section of diameter d, so proportioned by varying the diameter such that the maximum stress x at the surface due to bending is constant, when...

which of the wireless technologies requieres line of sight of communications

Keesha Co. borrows $260,000 cash on November 1, 2018, by signing a 180-day, 10% note with a face value of $260,000. 1. On what date does this note mature? 2. & 3. What is the amount of interest...

c Recalculate the intrinsic value of Honda using the three-stage growth model of Spreadsheet 13.1. Treat each of the following scenarios independently. A)ROE in the constant-growth period will be...