Electrical Engineering · Question Bank

Magnetic Circuits

28 of 84 questions match · page 1 of 2. Answer in your head first, then check the solution.

Study the lessons
TypeAll 84Problem solving 28Objective 56
DifficultyAll 28Easy 22Medium 5Hard 1
✕ Clear filters
#1📜 EE Pre-Board August 2012📘 PowerhouseEasy
What is the force between two wires carrying currents 10 and 50 A each? The lengths of the wires are 50 cm and are separated by 5 cm distance.
A0.005 N
B0.002 N
C0.001 N
D0.004 N
#2📜 EE Pre-Board August 2012📘 PowerhouseEasy
A magnetizing force of 1000 AT/m will produce a flux density of _ in air.
A0.63 mWb/m²
B0.63 Wb/m³
C1.257 mWb/m³
D1.257 Wb/m³
#3📜 EE Pre-Board August 2012📘 PowerhouseMedium
An iron ring 100 cm mean circumference is made from round iron of cross section \(10^{-3}\) m². Its relative permeability is 500. If it is wound with 250 turns, what current will be required to produce a flux of \(2 \times 10^{-3}\) Wb?
A21.47 A
B14.27 A
C12.74 A
D17.42 A
#4📜 EE Pre-Board March 2013📘 PowerhouseEasy
A current of 10 A is flowing in a flexible conductor of length 1.5 m. A force of 15 N acts on it when it is placed in a uniform field of 2 T. Calculate the angle between the magnetic field and the direction of the current.
A30°
B45°
C60°
D90°
#5📜 EE Pre-Board March 2013📘 PowerhouseEasy
Calculate the magnetic field intensity to produce a flux density of \(10 \times 10^{-3}\) tesla at the center of a long straight solenoid.
A6,423 AT/m
B7,958 AT/m
C8,323 AT/m
D7,869 AT/m
#6📜 EE Pre-Board March 2013📘 PowerhouseMedium
Determine the inductance L of a coil of 500 turns wound on an air cored torroidal ring having a mean diameter of 300mm. The ring has a circular cross section of diameter 50mm.
A\(6.54 \times 10^{-3}\) H
B\(6.54 \times 10^{-4}\) H
C\(3.27 \times 10^{-3}\) H
D\(3.27 \times 10^{-4}\) H
#7📜 EE Pre-Board August 2013📘 PowerhouseHard
An iron ring of circular cross-section of \(5 \times 10^{-4}\) m² has a mean circumference of 2 m. It has a saw-cut of \(2 \times 10^{-3}\) m length and is wound with 800 turns of wire. Determine the exciting current when the flux in the air gap is \(0.5 \times 10^{-3}\) Wb. Given μr of iron = 600 and leakage factor = 1.2. Assume the areas of air gap and iron are the same.
A2.95 A
B3.95 A
C4.95 A
D5.95 A
#8📜 EE Pre-Board August 2013📘 PowerhouseEasy
Two straight parallel wires 2 m long and 3 mm apart carry a current of 8 A in opposite directions. Calculate the force between these conductors.
A\(8.25 \times 10^{-3}\) N
B\(8.75 \times 10^{-3}\) N
C\(8.33 \times 10^{-3}\) N
D\(8.53 \times 10^{-3}\) N
#9📜 EE Pre-Board August 2013📘 PowerhouseEasy
An air cored coil has 500 turns. The mean length of magnetic flux path is 50 cm and the area of cross-section is \(5 \times 10^{-4}\) m² . If the exciting current is 5 A, determine the flux density.
A\(3.1415 \times 10^{-3}\) T
B\(3.1415 \times 10^{-4}\) T
C\(6.283 \times 10^{-3}\) T
D\(6.283 \times 10^{-4}\) T
#10📜 EE Pre-Board March 2014📘 PowerhouseEasy
A wire 36 inches long is carrying a current of 1,200 A. Find the flux density in gauss at a point 12 inches from the wire.
A2.4
B7.87
C6.31
D5.52
#11📜 EE Pre-Board March 2014📘 PowerhouseEasy
An air gap 1.1 mm long and 40 cm² in cross-section exists in a magnetic circuit. Determine the mmf required to create a flux of \(10 \times 10^{-4}\) Wb in the air gap.
A2.1885 AT
B21.885 AT
C218.85 AT
D2,188.5 AT
#12📜 EE Pre-Board August 2014📘 PowerhouseEasy
Two long straight conductors each carrying an electric current of 5A are kept parallel to each other at a separation of 2.5cm. Calculate the magnitude of magnetic force experienced by 10cm of a conductor.
A\(2 \times 10^{-3}\) N
B\(2 \times 10^{-4}\) N
C\(2 \times 10^{-5}\) N
D\(2 \times 10^{-6}\) N
#13📜 EE Pre-Board August 2014📘 PowerhouseMedium
An iron core has a cross-section of 500 mm² and a length of 100 cm. A magnetizing force of 500 AT in it produces a magnetic flux of 400 μWb. Determine the relative permeability of the material.
A1,275
B1,250
C1,225
D1,200
#14📜 EE Pre-Board March 2015📘 PowerhouseEasy
A horizontal powerline carries a current of 90 A. Compute the magnetic field at a point 1.5 m below the line.
A\(1.2 \times 10^{-5}\) T
B\(1.2 \times 10^{-4}\) T
C\(1.2 \times 10^{-3}\) T
D\(1.2 \times 10^{-2}\) T
#15📜 EE Pre-Board March 2015📘 PowerhouseEasy
A wire length 1 m carries a current of 10 A perpendicular to a field of flux density 0.5 T. Determine the magnitude of the force on the wire.
A5 N
B50 N
C10 N
D100 N
#16📜 EE Pre-Board March 2015📘 PowerhouseEasy
Two conductors carrying 50 amperes and 75 amperes respectively are placed 10 cm apart. Calculate the force between them per meter.
A0.075 N/m
B100 N/m
C0.0075 N/m
D10 N/m
#17📜 EE Pre-Board August 2015📘 PowerhouseEasy
The core of a certain magnetic circuit has a length of 5 cm and the inductance of the coil is 10 mH. What is the inductance of the same if the number of turns is reduced to 1/2 of the original? All other factors are unchanged.
A20 mH
B10 mH
C2.5 mH
D5.0 mH
#18📜 EE Pre-Board August 2015📘 PowerhouseEasy
An electromagnet has an air gap of 3 mm and the flux density in the gap is 1.257 Wb/m² . Calculate the ampere-turns required for the gap.
A2000
B2,500
C3,000
D4,000
#19📜 EE Pre-Board August 2015📘 PowerhouseEasy
Two long straight conductors each carrying an electric current of 5A are kept parallel to each other at a separation of 2.5cm. Calculate the magnitude of magnetic force experienced by 10cm of a conductor.
A\(5 \times 10^{-5}\) N
B\(4 \times 10^{-5}\) N
C\(3 \times 10^{-5}\) N
D\(2 \times 10^{-5}\) N
#20📜 EE Pre-Board March 2016📘 PowerhouseEasy
A current of 10 A is flowing in a flexible conductor of length 1.5 m. A force of 15 N acts on it when it is placed in uniform field of 2 T. Calculate the angle between the magnetic field and the direction of the current.
A90°
B60°
C45°
D30°

More Electrical Engineering topics