What is the primary concept behind magnetostatics?
A Magnetic fields
B Moving charges
C Electric fields
D Charge distribution
Magnetostatics is the study of magnetic fields in systems where the currents are steady (not changing with time). It deals with the behavior of magnetic fields generated by static or constant currents.
What does the concept of an electric dipole involve?
A Two equal and same charges
B A single charge in a field
C Two equal and opposite charges
D A moving charge
An electric dipole consists of two equal and opposite charges separated by a distance. The dipole moment is the product of the charge and the separation distance, and it plays a key role in electric fields.
What is permittivity a measure of in electromagnetism?
A Energy stored
B Charge density
C Ability to resist current
D Ability to allow electric field lines
Permittivity is a material property that measures how easily electric field lines can pass through a material. It influences the strength of the electric field in the material and is a key factor in capacitance.
What does Gauss’s law describe in terms of electric fields?
A Electric current
B Electric field flux
C Voltage
D Magnetic field strength
Gauss’s law states that the electric flux through any closed surface is proportional to the total charge enclosed within that surface. It is used to calculate electric fields in symmetrical charge distributions.
How does an electric dipole behave in an external electric field?
A It moves away
B It stays stationary
C It rotates
D It accelerates
In an external electric field, an electric dipole experiences a torque that causes it to rotate. The dipole aligns itself with the electric field direction, minimizing its potential energy.
What happens to the electric field strength as you move further away from an electric dipole?
A Increases
B Stays the same
C Becomes zero
D Decreases
The electric field strength of an electric dipole decreases with the square of the distance from the dipole. The field falls off faster than that of a point charge and behaves differently at large distances.
What does magnetostatics primarily deal with in terms of current?
A Static currents
B Alternating current
C Electric currents
D Magnetic flux
Magnetostatics is concerned with the magnetic fields generated by steady or static currents. It does not deal with time–varying magnetic fields, which are studied in electrodynamics.
What is the effect of permittivity on the capacitance of a capacitor?
A Decreases capacitance
B No effect
C Increases capacitance
D Changes resistance
Permittivity increases the capacitance of a capacitor. A higher permittivity material between the plates of a capacitor allows more charge to be stored for the same voltage, increasing the capacitance.
What type of material is often used to increase the strength of an electric field in a capacitor?
A Conductive material
B Magnetic material
C Superconductive material
D Dielectric material
A dielectric material is placed between the plates of a capacitor to increase its capacitance by reducing the electric field between the plates. It allows more charge to accumulate without discharging.
In the context of an electric dipole, what is the dipole moment?
A Magnitude of the electric field
B Net charge on the dipole
C Product of charge and separation distance
D Direction of the field
The dipole moment is defined as the product of the charge and the distance between the two charges. It is a vector quantity and plays a key role in the electric field behavior of dipoles.
What does Gauss’s law for magnetism state?
A Electric flux is zero
B Magnetic field lines are closed loops
C Magnetic flux through a surface is proportional to charge
D Magnetic fields do not exist
Gauss’s law for magnetism states that the net magnetic flux through a closed surface is zero, meaning that magnetic field lines always form closed loops, unlike electric fields which can begin and end at charges.
How does the electric field in a conductor behave in electrostatic equilibrium?
A Zero
B Non–zero and constant
C Varies with distance
D Fluctuates
In electrostatic equilibrium, the electric field inside a conductor is zero. Any excess charge resides on the surface of the conductor, and the electric field within the conductor is neutralized by the charges’ movement.
What happens to the force between two electric charges as the distance between them increases?
A Increases
B Stays the same
C Decreases
D Becomes zero
The force between two electric charges decreases with the square of the distance between them, as described by Coulomb’s law. This inverse square relationship means the force weakens as charges move further apart.
What type of electric field is produced by a uniformly charged infinite plane?
A Radial field
B Diverging field
C Varying field
D Uniform field
A uniformly charged infinite plane produces a uniform electric field that is constant in magnitude and direction, regardless of distance from the plane, due to the symmetry of the charge distribution.
What is the effect of increasing the permittivity of the medium between plates of a capacitor?
A Increases capacitance
B Decreases capacitance
C No effect
D Decreases resistance
Increasing the permittivity of the medium between the plates of a capacitor increases the capacitance. This is because a higher permittivity allows more charge to be stored for the same applied voltage, thereby increasing the capacitance.