To determine the SI unit of the electric field, we can use its definition in terms of force per unit charge or its relationship with electric potential. Both approaches should lead to the same SI unit.
Both derivations confirm that Volt per meter (V/m) is a valid SI unit for the electric field.
Correct Option: B) Volt per meter (V/m) is an SI unit of the electric field, derived from the relationship between electric potential and distance.
The electric field describes the force that a test charge would experience at any given point in space due to the presence of other charges. For a point charge, the electric field lines originate from or terminate on the charge and indicate the direction of the force on a positive test charge. We need to determine both the direction (inward/outward) and the shape (radial/circular) of these field lines for a positive point charge.
Correct Option: B) Radial and outward
The electric field lines around a positive point charge originate from the charge and extend outwards radially. This is because a positive test charge placed anywhere near it would experience a repulsive force, pushing it directly away from the central positive charge.
To determine the SI unit of electric potential, we need to recall its definition and the units of the quantities involved in its calculation. Electric potential is defined as the amount of work done per unit charge to move a test charge from a reference point to a specific point in an electric field.
Therefore, the SI unit of electric potential is the Volt.
C) Volt (V) — As derived, the Volt is the SI unit for electric potential, representing one Joule of work per Coulomb of charge.
The question asks about the relationship between the electric field strength and the distance from a point charge. This can be determined by recalling Coulomb's Law and the formula for the electric field due to a point charge.
B) It decreases. As shown by the formula \(E = k \frac{|Q|}{r^2}\), the electric field strength is inversely proportional to the square of the distance from the point charge. Therefore, as the distance increases, the electric field strength decreases.
The question asks for the quantity that represents the work done per unit charge when moving a charge between two points in an electric field. We need to recall the definitions of the given options in the context of electrostatics.
Correct Option: B) Electric potential
The question asks to identify the law used to calculate the electric field due to a point charge. We need to recall the fundamental laws of electromagnetism and their specific applications.
Correct Option: B) Coulomb's Law is used to calculate the force between two point charges, from which the electric field due to a single point charge can be derived.