Physics
Magnetism and Magnetic Effects
218 Questions
Magnetism and magnetic effects focus on the forces exerted by magnetic fields on moving charges and magnetic materials. Questions cover magnetic dipoles, flux density, the motion of charged particles, and electromagnetic relationships. It is a vital physics topic for government competitive exams.
Magnetic dipolesCharged particle motionMagnetic flux densityBar magnetsEarth magnetism
Magnetism and Magnetic Effects Questions
What is the ion gyroradius?
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The radius of the circular orbit of an ion in a magnetic field
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The radius of the elliptical orbit of an ion in a magnetic field
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The radius of the helical orbit of an ion in a magnetic field
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The radius of the random walk of an ion in a magnetic field
A
Correct answer
Explanation
The ion gyroradius is the radius of the circular orbit of an ion in a magnetic field. It is given by the following equation: ( r_i = \frac{m_i v_i}{q_i B} ), where ( m_i ) is the mass of the ion, ( v_i ) is the velocity of the ion, ( q_i ) is the charge of the ion, and ( B ) is the magnetic field strength.
What is the electron gyroradius?
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The radius of the circular orbit of an electron in a magnetic field
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The radius of the elliptical orbit of an electron in a magnetic field
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The radius of the helical orbit of an electron in a magnetic field
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The radius of the random walk of an electron in a magnetic field
A
Correct answer
Explanation
The electron gyroradius is the radius of the circular orbit of an electron in a magnetic field. It is given by the following equation: ( r_e = \frac{m_e v_e}{e B} ), where ( m_e ) is the mass of the electron, ( v_e ) is the velocity of the electron, ( e ) is the elementary charge, and ( B ) is the magnetic field strength.
What is the magnetic permeability of a vacuum?
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1
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0
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4π x 10^-7 T m/A
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8.85 x 10^-12 F/m
C
Correct answer
Explanation
The magnetic permeability of a vacuum is a constant, denoted by the symbol μ0, and its value is approximately 4π x 10^-7 T m/A.
What is the magnetic field intensity (H) in a region of space?
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The force per unit charge on a stationary charge.
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The force per unit current on a moving charge.
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The force per unit magnetic pole strength.
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The force per unit magnetic moment.
B
Correct answer
Explanation
Magnetic field intensity (H) is defined as the force per unit current on a moving charge.
What is the relationship between magnetic field intensity (H) and magnetic flux density (B) in a material?
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H = B
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H = B/μ
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H = μB
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H = μ/B
B
Correct answer
Explanation
The relationship between magnetic field intensity (H) and magnetic flux density (B) in a material is given by H = B/μ, where μ is the permeability of the material.
What is the relationship between magnetic flux density (B) and magnetic field intensity (H) in a vacuum?
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B = H
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B = H/μ
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B = μH
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B = μ/H
C
Correct answer
Explanation
In a vacuum, the relationship between magnetic flux density (B) and magnetic field intensity (H) is given by B = μH, where μ is the permeability of vacuum.
What is the name of the constant that appears in Gauss's law for magnetic fields?
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Permittivity of free space
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Permeability of free space
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Speed of light
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Elementary charge
B
Correct answer
Explanation
The constant that appears in Gauss's law for magnetic fields is the permeability of free space, denoted by (\mu_0).
What is the formula for calculating the energy stored in a magnetic field?
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$E = 1/2 * B^2 * V$
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$E = B * V$
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$E = 1/2 * B * V$
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$E = 1/2 * B^2 * V^2$
A
Correct answer
Explanation
The energy stored in a magnetic field is given by the formula $E = 1/2 * B^2 * V$, where E is the energy stored, B is the magnetic field strength, and V is the volume of the magnetic field.