Test physics

What is Coulomb's Law and how is it mathematically expressed?

• F = k * q1 * q2 * r^2

• F = k * (q1 + q2) / r

• F = k * |q1 * q2| / r^2, where F is the force, k is Coulomb's constant, q1 and q2 are the charges, and r is the distance between the charges.

• F = k * |q1 - q2| / r

How does the strength of an electric field relate to the distance from a charge?

• The strength of an electric field remains constant regardless of distance from a charge.

• The strength of an electric field increases with the distance from a charge.

• The strength of an electric field decreases linearly with the distance from a charge.

• The strength of an electric field decreases with the square of the distance from a charge.

What is the formula for calculating the electric field due to a point charge?

• E = Q / (4 * π * ε * r^2)

• E = k * |Q| / r^2

• E = k * Q * r^2

• E = k * |Q| * r

Describe the concept of electric field lines and their significance.

• Electric field lines represent the flow of electric current in a circuit.

• Electric field lines are used to measure temperature changes.

• Electric field lines are significant as they help visualize electric fields, understand the behavior of charges, and analyze forces acting on charged particles.

• Electric field lines indicate the speed of sound in a medium.

What is the principle of superposition in electric fields?

• The electric field is only influenced by the nearest charge.

• Electric fields can only be calculated for a single charge at a time.

• The total electric field is the vector sum of the electric fields from all individual charges.

• The principle of superposition states that electric fields repel each other.

How do you calculate the force between two point charges?

• F = m * a

• F = q * E

• F = p * v

• F = k * |q1 * q2| / r^2

What is the relationship between electric field and potential difference?

• The electric field is the negative gradient of the potential difference.

• The electric field increases with decreasing potential difference.

• The electric field is the same as the potential difference.

• The electric field is independent of potential difference.

Define magnetic field and its unit of measurement.

• Magnetic field is measured in Volts (V).

• Magnetic field is measured in Newtons (N).

• Magnetic field is measured in Amperes (A).

• Magnetic field is measured in Tesla (T).

What is the right-hand rule in determining the direction of magnetic fields?

• The right-hand rule is used to determine the speed of electric currents.

• The right-hand rule states that the left thumb indicates the direction of the magnetic field.

• The right-hand rule states that if you point your right thumb in the direction of current, your fingers will curl in the direction of the magnetic field.

• The right-hand rule indicates that if you point your left thumb in the direction of the magnetic field, your fingers will curl in the direction of current.

How does the magnetic field around a current-carrying wire behave?

• The magnetic field is always directed towards the wire.

• The magnetic field is uniform and does not change with distance.

• The magnetic field only exists at the ends of the wire.

• The magnetic field around a current-carrying wire forms concentric circles and its direction is determined by the right-hand rule.