# 7 FE Electrical and Computer Practice Problems with Solutions

In this article, we are discussing 5 important sample questions of FE electrical and computer CBT exam with detailed solutions. Read FE Electrical and Computer Practice Problems answers below.

#### Q1. The only point of inflection on the curve representing the equation y = x^{3} + x^{2} – 3 is at:

A. x = -2/3

B. x = -1/3

C. x = 0

D. x = 1/3

**Solution: **f(x) = x

^{3}+ x

^{2}– 3

Inflection point occurs when f “(x) = 0

f'(x) = 3x

^{2}+ 2x

f “(x) = 6x + 2

Set equal to zero

6x + 2 = 0

x = –1/3

f “(x) is negative below x = –1/3 and positive above x = –1/3

Since f “(x) = 0 and f “(x) changes signs at x = –1/3, the inflection point is at x = –1/3.

THE CORRECT ANSWER IS: B

#### Q2. As a professional engineer originally licensed 30 years ago, you are asked to evaluate a newly developed computerized control system for a public transportation system. You may accept this project if:

A. you are competent in the area of modern control systems

B. you do not live in the jurisdiction where the transportation system is being installed

C. your original area of specialization was in transportation systems

D. you have regularly attended meetings of a professional engineering society

Solution:

Refer to the NCEES Rules of Professional Conduct.

THE CORRECT ANSWER IS: A

#### Q3. If $500 is invested at an annual interest rate of 8% per year, its future worth at the end of 30 years will be most nearly:

A. $1,200

B. $1,700

C. $5,031

D. $15,000

Solution:

F = 500(F/P, 8%, 30)

= 500 (10.0627)

= $5,031

THE CORRECT ANSWER IS: C

#### Q4. In the circuit shown, voltage V_{0} (V) is most nearly:

A. 19.5

B. 18.5

C. 16.5

D. 3.0

Apply KCL to the node marked V0:

19.5

THE CORRECT ANSWER IS: A

#### Q5. An industrial plant load is rated at 2.8 MVA at 0.7 pf lagging. If a capacitor bank rated at 3 MVA is added to the load, the new overall power factor of the system is most nearly:

**A. 0.9 leading**

B. 0.9 lagging

C. 0.6 leading

D. 0.6 lagging

B. 0.9 lagging

C. 0.6 leading

D. 0.6 lagging

Solution

P_{L} = 2.8 (0.7) = 1.96 MW

Q_{L} = 2.8 sin[cos^{–1} 0.7] = 2 Mvar

S_{L} = P_{L} + jQ_{L} = 1.96 + j2 MVA

S = S_{L} + S_{C} = (1.96 + j2) + (–j3) = 1.96 – j1 = 2.2 ∠–27° MVA

pf = cos(–27°) = 0.89 leading

#### Q6. Which of the following is true of the electric field intensity about an isolated point charge?

A. It varies directly as the distance to the charge.

B. It varies inversely as the distance to the charge.

C. It varies directly as the square of the distance to the charge.

D. It varies inversely as the square of the distance to the charge.

Solution:

The formula for electric field intensity can be found in Electrostatic Fields in the Electrical and Computer Engineering section of the FE Reference Handbook.

This formula is where r is the distance. Since r^{2} is in the denominator, E varies inversely as the square of the distance to the charge.

THE CORRECT ANSWER IS: D

#### The binary number 1011 corresponds to the decimal number:

A. 3

B. 10

C. 11

D. 15

Solution

1011 = (1×2^{3}) + (0x2^{2}) + (1×2) + (1×2^{0})

= 8 + 0 + 2 + 1 = 11