DFCCIL ELECTRICAL QUIZ |_00.1
Engineering Jobs   »   Quiz: Electrical Engineering 08 May 2021

Quiz: Electrical Engineering 08 May 2021

Quiz: Electrical Engineering
Exam: DFCCIL
Topic: Magnetic circuit

Each question carries 1 mark.
Negative marking: 1/4 mark
Time: 10 Minute

Q1. An emf of 16 volts is induced in a coil of inductance 4 H. The rate of change of current must be
(a) 4 A/s
(b) 16 A/s
(c) 32 A/s
(d) 64 A/s

Q2. In case of all flux from the current in coil 1 links with coil 2, the coefficient of coupling will be
(a) Zero
(b) 0.5
(c) 1.0
(d) 2.0

Q3. The magnetic field due to an infinite linear current carrying conductor is
(a) H = μi/2πr A/m.
(b) H = i/2πr A/m.
(c) H = μi/(2r ) A/m
(d) H = i/r A/m

Q4. Area of hysteresis loop represents
(a) copper loss
(b) eddy current loss
(c) dielectric loss
(d) Energy loss to magnetize and demagnetize the core

Q5. Two coils have inductances of 8 mH and 18 mH and a co-efficient of coupling of 0.5. If
the two coils are connected in series aiding, the total inductance will be
(a) 32 mH
(b) 38 mH
(c) 40 mH
(d) 48 mH

Q6. The energy in joules stored in the magnetic field of 0.15 H inductance with a 180mA
current will be
(a) 2.43
(b) 2.43×10^(-3)
(c) 2.43×10^(-6)
(d) 2.43×10^(-9)

Q7. What is the inductive reactance if the Q of a coil is 60, and the winding resistance is 5 Ω?
(a) 12 Ω
(b) 300 Ω
(c) 30 Ω
(d) 0.083 Ω

Q8. Inductance is:
(a) directly proportional to the length of the coil
(b) directly proportional to the number of turns on the coil
(c) inversely proportional to the cross-sectional area of the coil
(d) inversely proportional to the permeability

Q9. What is the total inductance, assuming no mutual inductance?

DFCCIL ELECTRICAL QUIZ |_40.1

(a) 0 mH
(b) 6 mH
(c) 12 mH
(d) 0.73 mH

Q10. Mutual inductance between two magnetically coupled coils depends on
(a) Permeability of the core material
(b) Number of turns of the coils
(c) The cross-sectional area of their common core
(d) All of the above

SOLUTIONS
S1. Ans.(a)
Sol. e=L dI/dt
dI/dt=(induced emf)/inductance=16/4=4 A/s

S2. Ans.(c)
Sol. If all flux from the current in coil 1 links with coil 2, then that is referred as an ideal coupling. For an ideal coupling, the coefficient coupling is 1. Any other coupling the coupling co-efficient is always less than 1.

S3. Ans.(b)
Sol. Magnetic field, H=i/2πr A/m

S4. Ans.(d)
Sol. Energy loss due to magnetize and demagnetize the core.

S5. Ans.(b)
Sol. L_1=8 mH L_2=18 mH
K= 0.5
Total inductance
=L1+L2+2M
where; M=K√(L1*L2 )

Total inductance=8+18+2 X 0.5√144
=26+12=38 mH

S6. Ans.(b)
Sol. Energy stored in magnetic field
=1/2 LI²
=1/2×0.15×(0.18)^2
=2.43×10^(-3) J

S7. Ans.(b)
Sol. Q=XC/R=XC/5=60
∴Inductive reactance=XC=60×5=300 Ω

S8. Ans.(b)
Sol. inductance of a coil (L)=(N^2µA)/l

S9. Ans.(c)
Sol. for series connection of inductance: Leqv=L1+L2+L3=1+5+6=12 mH

S10. Ans.(d)
Sol. The expression of the mutual inductance between two magnetically coupled coils is as follows;

DFCCIL ELECTRICAL QUIZ |_50.1

Where, μr = Relative permeability of core N = The number of the turns of the coil A = Cross sectional area of their common core Hence, the mutual inductance depends on all the above factors.

Sharing is caring!

×

Download success!

Thanks for downloading the guide. For similar guides, free study material, quizzes, videos and job alerts you can download the Adda247 app from play store.

Thank You, Your details have been submitted we will get back to you.

Was this page helpful?

Leave a comment

Your email address will not be published. Required fields are marked *

Join India's largest learning destination

What You Will get ?

  • Job Alerts
  • Daily Quizzes
  • Subject-Wise Quizzes
  • Current Affairs
  • Previous year question papers
  • Doubt Solving session

Login

OR

Forgot Password?

Join India's largest learning destination

What You Will get ?

  • Job Alerts
  • Daily Quizzes
  • Subject-Wise Quizzes
  • Current Affairs
  • Previous year question papers
  • Doubt Solving session

Sign Up

OR
Join India's largest learning destination

What You Will get ?

  • Job Alerts
  • Daily Quizzes
  • Subject-Wise Quizzes
  • Current Affairs
  • Previous year question papers
  • Doubt Solving session

Forgot Password

Enter the email address associated with your account, and we'll email you an OTP to verify it's you.


Join India's largest learning destination

What You Will get ?

  • Job Alerts
  • Daily Quizzes
  • Subject-Wise Quizzes
  • Current Affairs
  • Previous year question papers
  • Doubt Solving session

Enter OTP

Please enter the OTP sent to
/6


Did not recive OTP?

Resend in 60s

Join India's largest learning destination

What You Will get ?

  • Job Alerts
  • Daily Quizzes
  • Subject-Wise Quizzes
  • Current Affairs
  • Previous year question papers
  • Doubt Solving session

Change Password



Join India's largest learning destination

What You Will get ?

  • Job Alerts
  • Daily Quizzes
  • Subject-Wise Quizzes
  • Current Affairs
  • Previous year question papers
  • Doubt Solving session

Almost there

Please enter your phone no. to proceed
+91

Join India's largest learning destination

What You Will get ?

  • Job Alerts
  • Daily Quizzes
  • Subject-Wise Quizzes
  • Current Affairs
  • Previous year question papers
  • Doubt Solving session

Enter OTP

Please enter the OTP sent to Edit Number


Did not recive OTP?

Resend 60

By skipping this step you will not recieve any free content avalaible on adda247, also you will miss onto notification and job alerts

Are you sure you want to skip this step?

By skipping this step you will not recieve any free content avalaible on adda247, also you will miss onto notification and job alerts

Are you sure you want to skip this step?