Question: Suppose the resistor in Problem 7.33 is rotated so that its axis is aligned with the flow. What is the maximum permissible power dissipation? From

Suppose the resistor in Problem 7.33 is rotated so that its axis is aligned with the flow. What is the maximum permissible power dissipation? From Problem 7.33: An electronic circuit contains a power resistor that dissipates 1.5 watts. The designer wants to modify the circuitry in such a way that it will be necessary for the resistor to dissipate 2.5 watts. The resistor is in the shape of a disk 1 cm in diameter and 0.6 mm thick. Its axis aligned with a cooling air flow at 30?C and 10 m/s velocity. The resistor lifetime becomes unacceptable if its surface temperature exceeds 90?C. Is it necessary to replace the resistor for the new circuit?GIVENA heat generating resistor disk with its axis aligned with a cooling airflowHeat generation rate (QG) = 2.5 WDisk diameter (D) = 1 cm = 0.01 mDisk thickness (t) = 0.6 mm = 0.0006 mAir temperature (T??) = 30?CAir velocity (U??) = 10 m/sMaximum surface temperature (Ts) = 90?CASSUMPTIONSHeat transfer from the edges is negligibleThe heat flux is equal from bothfaces

Alr T--30C U= 10 m/s D31 cm ww go =!

Step by Step Solution

★★★★★

3.53 Rating (156 Votes )

There are 3 Steps involved in it

1 Expert Approved Answer

Step: 1 Unlock

The Reynolds number based on the film temperature is unchanged from Problem 733 Re Df 5155 T... 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)

66-E-M-E-H-M-T (1817).docx

120 KBs Word File

Students Have Also Explored These Related Mechanical Engineering Questions!

An electronic circuit contains a power resistor that dissipates 1.5 watts. The designer wants to modify the circuitry in such a way that it will be necessary for the resistor to dissipate 2.5 watts....

The value of R for the resistor in Problem 9 is increased by a factor of 2.5 while the current is kept fixed. By what factor does the average power change?

The resistor in Problem 46 is replaced by an ideal voltmeter.(a) To which rail should the positive meter terminal be connected if it?s to indicate a positive voltage?(b) At what rate does the agent...

Suppose the coil of Problem 88 is rotated about its horizontal centerline at constant angular velocity of 2 rad/s. Find the induced current as a function of time.

Suppose the coil of Problem 88 is rotated about its vertical centerline at constant angular velocity of 2 rad/s. Find the induced current as a function of time.

1. A circle, centered at the origin with radius r, is shown below along with the equation for the top half of the circle. Whole circle: x2+ 312: r2 Top half of circle: y = \\/ r2 x2 a. Suppose the...

How do I solve this? 1. R X N Y C=luf Z figure 4 In your laboratory kit you find an unlabeled inductor. Let R be its internal resistance and L be its inductance. You quickly determine R to be 35 Ohms...

Problem 7-33 (Static) Suppose there are two independent economic factors, M and The risk-free rate is 7%, and all stocks have independent firm-specific components with a standard deviation of 50%....

Problem 7-33 (Static) Suppose there are two independent economic factors, M and M. The risk-free rate is 7%, and all stocks have independent firm-specific components with a standard deviation of 50%....

Problem 7-33 (Algo) Suppose there are two independent economic factors, M1 and M2. The risk-free rate is 5%, and all stocks have independent firm-specific components with a standard deviation of 52%....

The local motorcycle dealership has a sale to clear out its inventory from last years models. The dealership has two options for you: Option 1: $35,000 (price) with 0% interest financing for six...

Backlund Farm Supply completed the work sheet on page 607 for the year ended December 31, 20--. Owner's equity as of January 1, 20--, was $50,000. The current portion of Mortgage Payable is $1,000....

Quantitative Problem 3 : Assume today is December 3 1 , 2 0 1 7 . Imagine Works Inc. just paid a dividend of $ 1 . 3 0 per share at the end of 2 0 1 7 . The dividend is expected to grow at 1 2 % per...

Phillips Corporations fiscal year ends on November 30. The following accounts are found in its job order cost accounting system for the first month of the new fiscal year. Other data: 1. On December...

Who is generally involved and what information is typically carried in downward, upward, and horizontal communication channels?

Lott Company uses a job order cost system and applies overhead to production on the basis of direct labor costs. On January 1, 2017, Job 50 was the only job in process. The costs incurred prior to...

Empire Company is a manufacturer of smart phones. Its controller resigned in October 2017. An inexperienced assistant accountant has prepared the following income statement for the month of October...

Bell Company, a manufacturer of audio systems, started its production in October 2012. For the preceding 3 years, Bell had been a retailer of audio systems. After a thorough survey of audio system...

In this chapter, you learned that the money multiplier is calculated as one divided by the required reserve ratio. This definition implicitly assumes that banks are not holding excess reserves. Would...

A hair dryer may be idealized as a circular duct through which a small fan draws ambient air and within which the air is heated as it flows over a coiled electric resistance wire. Surroundings, Tur...

In one stage of an annealing process, 304 stainless steel sheet is taken from 300 K to 1250 K as it passes through an electrically heated oven at a speed of V, = 10 mm/s. The sheet thickness and...

Annealing, an important step in semiconductor materials processing, can be accomplished by rapidly heating the silicon wafer to a high temperature for a short period of time. The schematic shows a...

Belief in Haunted Places A random sample of 340 college students were asked if they believed that places could be haunted, and150 responded yes. Estimate the true proportion of college students who...

Suppose that B2B, Inc., has a capital structure of 36 percent equity, 16 percent preferred stock, and 48 percent debt. Assume the before-tax component costs of equity, preferred stock, and debt are...

You want to create a portfolio equally as risky as the market, and you have $250,000 to invest. Given this information, fill in the three missing pieces of information in the following table. Show...