Units Flashcards
What is Coulomb’s law?
F = k q1q2 / r²
This law describes the force between two charged objects.
What is the formula for the electric field intensity (E) at a distance r from a point charge q?
E = 1 / (4πε0 r²) * q
This equation describes the electric field created by a point charge.
Define electric dipole moment (m).
m = q * d
where q is the charge and d is the separation distance.
What is the electric field intensity on the axial line of an electric dipole at a distance r?
E = (1 / (4πε0)) * (2p / r³)
where p is the dipole moment.
What is Gauss’s law?
∮ E ⋅ dS = Q_enc / ε0
This law relates the electric flux through a closed surface to the charge enclosed.
What is the relationship between electric field (E) and electric potential (V)?
E = -dV/dr
This relationship indicates how the electric field is the negative gradient of the electric potential.
What is the formula for electric potential (V) at a distance r from a point charge q?
V = q / (4πε0 r)
This formula calculates the electric potential due to a point charge.
What is the capacitance of a spherical conductor of radius R?
C = 4πε0R
This equation gives the capacitance of a spherical conductor.
What is the formula for energy stored in a capacitor?
U = 1/2 CV²
This equation calculates the energy stored based on capacitance and voltage.
What is the relationship for resistors in series?
R_total = R1 + R2 + … + Rn
This relationship indicates that the total resistance is the sum of individual resistances.
What is the formula for the magnetic field (B) at a point due to a straight wire carrying current I?
B = (μ0 I) / (2πr)
This formula describes the magnetic field at a distance r from a straight conductor.
What is the force on a charged particle in a uniform electric field?
F = qE
This formula indicates the force experienced by a charge in an electric field.
What is the torque on an electric dipole in a uniform electric field?
τ = p × E
where p is the dipole moment and E is the electric field.
What is the formula for the electric field due to a uniformly charged spherical shell?
E = 0 for r < R and E = (1 / (4πε0)) * (q / r²) for r > R
This describes how the electric field behaves inside and outside a charged spherical shell.
What is the relationship between current density (J), charge density (n), and drift velocity (v_d)?
J = n e v_d
This formula connects current density with charge density and drift velocity.
What is the formula for the force on a current-carrying conductor in a magnetic field?
F = I (l × B)
where I is current, l is the length of the conductor, and B is the magnetic field.
What is the potential energy (U) of a magnetic dipole in a magnetic field?
U = -M ⋅ B
where M is the magnetic moment and B is the magnetic field.
What is the formula for the electric field due to a thin non-conducting infinite sheet of charge?
E = σ / (2ε0)
where σ is the surface charge density.
Fill in the blank: The capacitance of an air-filled parallel plate capacitor is _______.
C = ε0 A / d
where A is the area of the plates and d is the separation between them.
What is the formula for the magnetic field due to a circular coil of radius a carrying current I?
B = (μ0 NI) / (2a)
where N is the number of turns in the coil.
What is the condition for electric field intensity (E) at very large distances from an electric dipole?
E = (1 / (4πε0)) * (2p / r³)
This describes the electric field intensity of a dipole as distance increases.
What is Bequatorial in terms of magnetic moment?
Bequatorial = µ0 M
Where µ0 is the permeability of free space and M is the magnetization.
What is the relationship between current (I) and deflection (q) in a moving coil galvanometer?
I ∝ q or I = Gq
Where G is the galvanometer constant.
What does Gauss’s law for magnetism state?
φ = ∑ B⋅ΔS = 0
This law indicates that the total magnetic flux through a closed surface is zero.
