Q. A magnetic dipole moment is defined as the product of which two quantities? (2022)
A.
Current and area
B.
Magnetic field and area
C.
Magnetic field and current
D.
Current and resistance
Show solution
Solution
The magnetic dipole moment (μ) is defined as the product of the current (I) flowing through a loop and the area (A) of the loop, μ = I × A.
Correct Answer: A — Current and area
Learn More →
Q. A magnetic field is produced by which of the following? (2021)
A.
Static electric charges
B.
Moving electric charges
C.
Magnetic monopoles
D.
None of the above
Show solution
Solution
A magnetic field is produced by moving electric charges, such as those in a current-carrying wire.
Correct Answer: B — Moving electric charges
Learn More →
Q. The Earth's magnetic field is approximately how many times weaker than that of a typical refrigerator magnet? (2023)
A.
10 times
B.
100 times
C.
1000 times
D.
10000 times
Show solution
Solution
The Earth's magnetic field is approximately 1000 times weaker than that of a typical refrigerator magnet.
Correct Answer: C — 1000 times
Learn More →
Q. The force experienced by a charged particle moving in a magnetic field is given by which law? (2020)
A.
Coulomb's Law
B.
Lorentz Force Law
C.
Faraday's Law
D.
Ampere's Law
Show solution
Solution
The force experienced by a charged particle moving in a magnetic field is described by the Lorentz Force Law, F = q(v × B).
Correct Answer: B — Lorentz Force Law
Learn More →
Q. The force experienced by a charged particle moving in a magnetic field is maximum when the angle between the velocity and magnetic field is: (2020)
A.
0 degrees
B.
90 degrees
C.
180 degrees
D.
45 degrees
Show solution
Solution
The force (F) on a charged particle in a magnetic field is given by F = qvB sin(θ). The force is maximum when θ = 90 degrees, as sin(90) = 1.
Correct Answer: B — 90 degrees
Learn More →
Q. The force on a charged particle moving in a magnetic field is given by which law? (2021)
A.
Coulomb's Law
B.
Lorentz Force Law
C.
Faraday's Law
D.
Ampere's Law
Show solution
Solution
The force (F) on a charged particle moving in a magnetic field is described by the Lorentz Force Law, F = q(v × B), where q is the charge, v is the velocity, and B is the magnetic field.
Correct Answer: B — Lorentz Force Law
Learn More →
Q. The force on a charged particle moving in a magnetic field is maximum when the angle between the velocity and magnetic field is: (2021)
A.
0 degrees
B.
90 degrees
C.
180 degrees
D.
45 degrees
Show solution
Solution
The force on a charged particle in a magnetic field is given by F = qvB sin(θ). The force is maximum when sin(θ) = 1, which occurs at θ = 90 degrees.
Correct Answer: B — 90 degrees
Learn More →
Q. The magnetic field due to a straight current-carrying conductor at a distance r from the wire is given by which formula? (2019)
A.
B = μ₀I/(2πr)
B.
B = μ₀I/(4πr²)
C.
B = μ₀I/(2r)
D.
B = μ₀I/(πr)
Show solution
Solution
The magnetic field (B) due to a straight current-carrying conductor at a distance r is given by B = μ₀I/(2πr).
Correct Answer: A — B = μ₀I/(2πr)
Learn More →
Q. The magnetic field due to a straight current-carrying conductor at a distance r is given by which formula? (2022)
A.
B = μ₀I/2πr
B.
B = μ₀I/r
C.
B = μ₀I/4πr²
D.
B = μ₀I/2r
Show solution
Solution
The magnetic field (B) at a distance r from a straight current-carrying conductor is given by B = μ₀I/2πr.
Correct Answer: A — B = μ₀I/2πr
Learn More →
Q. The magnetic field inside a long solenoid is given by which of the following expressions? (2020)
A.
μ₀nI
B.
μ₀I/n
C.
nI/μ₀
D.
I/μ₀n
Show solution
Solution
The magnetic field (B) inside a long solenoid is given by B = μ₀nI, where n is the number of turns per unit length and I is the current.
Correct Answer: A — μ₀nI
Learn More →
Q. The magnetic field lines around a straight current-carrying conductor are in which shape? (2022)
A.
Straight lines
B.
Concentric circles
C.
Ellipses
D.
Spirals
Show solution
Solution
The magnetic field lines around a straight current-carrying conductor form concentric circles centered around the wire.
Correct Answer: B — Concentric circles
Learn More →
Q. The magnetic field lines around a straight current-carrying conductor are: (2022)
A.
Straight lines
B.
Concentric circles
C.
Elliptical
D.
Random
Show solution
Solution
The magnetic field lines around a straight current-carrying conductor form concentric circles centered around the wire.
Correct Answer: B — Concentric circles
Learn More →
Q. The magnetic field lines inside a bar magnet are directed from: (2019)
A.
North to South
B.
South to North
C.
East to West
D.
West to East
Show solution
Solution
The magnetic field lines inside a bar magnet are directed from the North pole to the South pole.
Correct Answer: A — North to South
Learn More →
Q. What happens to the magnetic field inside a solenoid when the current is increased? (2020)
A.
It decreases
B.
It remains constant
C.
It increases
D.
It becomes zero
Show solution
Solution
The magnetic field inside a solenoid is directly proportional to the current. Therefore, if the current is increased, the magnetic field also increases.
Correct Answer: C — It increases
Learn More →
Q. What is the direction of the magnetic field inside a current-carrying circular loop? (2019)
A.
Out of the plane
B.
Into the plane
C.
Clockwise
D.
Counterclockwise
Show solution
Solution
Using the right-hand rule, if the current flows in a counterclockwise direction, the magnetic field inside the loop points out of the plane.
Correct Answer: A — Out of the plane
Learn More →
Q. What is the direction of the magnetic field inside a current-carrying solenoid? (2019)
A.
From south to north
B.
From north to south
C.
Perpendicular to the axis
D.
Radially outward
Show solution
Solution
The magnetic field inside a current-carrying solenoid is directed from the north pole to the south pole of the solenoid.
Correct Answer: B — From north to south
Learn More →
Q. What is the effect of increasing the number of turns in a solenoid on its magnetic field strength? (2022)
A.
Decreases the field strength
B.
Increases the field strength
C.
No effect
D.
Reverses the field direction
Show solution
Solution
Increasing the number of turns (n) in a solenoid increases the magnetic field strength, as B = μ₀nI.
Correct Answer: B — Increases the field strength
Learn More →
Q. What is the effect of placing a ferromagnetic material in a magnetic field? (2023)
A.
It becomes a magnet
B.
It repels the magnetic field
C.
It has no effect
D.
It weakens the magnetic field
Show solution
Solution
When a ferromagnetic material is placed in a magnetic field, it becomes magnetized and can retain its magnetism even after the external field is removed.
Correct Answer: A — It becomes a magnet
Learn More →
Q. What is the effect of placing a ferromagnetic material inside a solenoid? (2023)
A.
Decreases the magnetic field
B.
Increases the magnetic field
C.
No effect
D.
Reverses the magnetic field
Show solution
Solution
Placing a ferromagnetic material inside a solenoid increases the magnetic field due to the material's high magnetic permeability.
Correct Answer: B — Increases the magnetic field
Learn More →
Q. What is the formula for the magnetic field at the center of a circular loop of radius r carrying a current I? (2023)
A.
B = μ₀I/2r
B.
B = μ₀I/r
C.
B = μ₀I/4r
D.
B = μ₀I/πr
Show solution
Solution
The magnetic field (B) at the center of a circular loop is given by B = μ₀I/2r.
Correct Answer: A — B = μ₀I/2r
Learn More →
Q. What is the magnetic moment of a circular loop of radius r carrying a current I? (2021)
A.
πr²I
B.
2πrI
C.
Ir²
D.
πrI
Show solution
Solution
The magnetic moment (μ) of a circular loop is given by μ = I × A, where A is the area of the loop. For a circular loop, A = πr², thus μ = I × πr² = πr²I.
Correct Answer: A — πr²I
Learn More →
Q. What is the principle behind the working of a galvanometer? (2023)
A.
Electromagnetic induction
B.
Magnetic force on a current-carrying conductor
C.
Electrostatic force
D.
Magnetic field lines
Show solution
Solution
A galvanometer works on the principle of the magnetic force acting on a current-carrying conductor placed in a magnetic field.
Correct Answer: B — Magnetic force on a current-carrying conductor
Learn More →
Q. What is the relationship between magnetic field strength and distance from a long straight conductor? (2023)
A.
Increases with distance
B.
Decreases with distance
C.
Remains constant
D.
Increases then decreases
Show solution
Solution
The magnetic field strength around a long straight conductor decreases with distance from the conductor, following the inverse relationship.
Correct Answer: B — Decreases with distance
Learn More →
Q. What is the SI unit of magnetic field strength? (2023)
A.
Tesla
B.
Weber
C.
Henry
D.
Ampere
Show solution
Solution
The SI unit of magnetic field strength is the Tesla (T).
Correct Answer: A — Tesla
Learn More →
Q. What is the SI unit of magnetic moment? (2023)
A.
Ampere-meter
B.
Tesla
C.
Joule per Tesla
D.
Newton per Ampere
Show solution
Solution
The SI unit of magnetic moment is Joule per Tesla (J/T), which can also be expressed as Ampere-meter squared (A·m²).
Correct Answer: C — Joule per Tesla
Learn More →
Q. What is the unit of magnetic moment? (2023)
A.
Ampere-meter
B.
Tesla
C.
Weber
D.
Newton-meter
Show solution
Solution
The unit of magnetic moment is Ampere-meter (A·m²).
Correct Answer: A — Ampere-meter
Learn More →
Q. Which of the following materials is considered a ferromagnetic material? (2021)
A.
Copper
B.
Aluminum
C.
Iron
D.
Gold
Show solution
Solution
Iron is a ferromagnetic material, which means it can be magnetized and retains its magnetic properties.
Correct Answer: C — Iron
Learn More →
Showing 1 to 27 of 27 (1 Pages)