Fields- Answers for Q.

  1. Main Features: Electric fields arise from electric charges, while gravitational fields originate from masses. Electric fields can be both attractive and repulsive (positive and negative charges), whereas gravitational fields are always attractive. The strength of electric fields can change significantly with distance while gravitational fields decrease less dramatically as distance increases.

  2. Gravitational Field Outside Spherical Bodies: The gravitational field outside spherical bodies like Earth behaves as if all of the mass were concentrated at a point at the center of the body. According to Newton's law of universal gravitation, the force decreases with the square of the distance from the center.

  3. Field Lines: Field lines in electric and gravitational fields represent the direction and

    strength of the field. The density of field lines indicates the strength of the field; closer lines mean a stronger field. For electric fields, field lines point away from positive charges and towards negative charges, while gravitational field lines point towards mass.

  4. Equipotential Surfaces: Equipotential surfaces are surfaces on which the gravitational or electric potential is the same. They are perpendicular to field lines, meaning that no work is needed to move a charge or mass along these surfaces. For point charges, the equipotential surfaces are spherical shells around the charge.

  5. Calculating Net Potential and Resultant Field Strength: To calculate the net potential and resultant field strength from multiple point charges/masses, you sum up the potentials (which are scalar quantities) from each point charge/mass at a given position. The resultant electric field due to multiple charges is determined by vector addition of the individual field vectors from each charge/mass.

  6. ΔUP = mgΔh: This equation is applicable in situations where an object is moving in a uniform gravitational field (where g is constant) and the height change (Δh) is within a relatively small vertical range compared to the radius of the Earth, such as for small elevations on Earth's surface.