CWI test exam question. 3

[mmccarrell]

I know this has been asked before. But can anyone tell me to what extent the CWI exam has as far as math questions? Are there certain formula's you have to calculate and are the questions multiple choice? The math is the only thing that has me worried. Sorry if I'm asking repiticious questions, but I'm studying hard for this.

 

[Eddycurrentguy]

Everyone hates the thought of math questions, but the math for the CWI is fairly basic.

You should be able to convert fractions to decimals, calculate tensile strength using load/area, perform basic addition and subtraction, and work with percentages for the code/specific part of the test.

ASNT publishes a guide for test taking...the principals for the CWI are identical.

Good luck...study hard and you will be ok...

http://www.asnt.org/publications/materialseval/basics/mar97basics/mar97bas.htm

 

[DVWE]

The one thing that comes to my mind is that you have to be able to calculate ultimate tensile strength. For example, you have a .75" x .75" coupon that broke at a load of 50,000 lbs, what is the ultimate tensile strength? Quite common question.
.75 x .75 = .5625 in2. (Area)
50,000 lb/.5625 in2 = 88,888 lb/in2.

Also, be able to back calculate that question, if it were asked like, calculate the load the test coupon broke at if the ultimate tensile strength is 88,888 lb/in2 and the area of the coupon is .5625 in2.
x/.5625 in2 = 88,888 lb/in2
x = 88,888 lb/in2 * .5625 in2
x = 50,000 lb

What is the area of the coupon if the load is 50,000 lb and the ultimate tensile strength is 88,888 lb/in2?
50,000 lb/x = 88,888 lb/in2
x = 50,000 lb/88,888 lb/in2
x = .5625 in2

 

[mmccarrell]

Thanks guys, both excellent answers. I hate to ask as I went back a ways and lots of questions were asked about it, but it always improves confidence when knowledgable people give some help. I will work on these solutions and if I pass, I'll post it, and again, thanks for replying.

 

[nde3rich]

Is DVUE Roger? If so check my post in ASME

Richard S.
ASNT NDT Level III
API 510,570,653, AWS-CWI

 

[DVWE]

No, not Roger here. I did read thru your post though, and I think the guys that have responded are correct.

 

[Ron]

Although you can probably get by without it, a little trig knowledge is helpful....not just for the test, but for your job as a CWI. If you plan to get into nondestructive testing (UT/RT) you'll need it.