The following link is a video on how Scientists visualise Magnetic Field lines.
Although we are dealing with Electric Field in this chapter, the video also provides insight into how we can visualise Electric fields.
The main difference from Magnetic field illustrated is the plane in which Electric field should emanate from the objects.
Otherwise, the visualisation of fluctuations and presence of Electric field around us is a good takeaway.
The main difference from Magnetic field illustrated is the plane in which Electric field should emanate from the objects.
Otherwise, the visualisation of fluctuations and presence of Electric field around us is a good takeaway.
To minus or not?
For this chapter,
When you are dealing with vectors; F or E,
DO NOT Include the minus sign of the charges.
Solve equation as per normal.
only consider the direction of these vectors towards the conclusion of the answer.
Tutorial Question 1
Hint
Answer
Main learning points
Hint
Answer
Main learning points
- For a position with zero resultant force, the magnitude of opposing forces (2 forces in this question) are the same.
- Let the unknown position r be a distance away from one of the charges.
- (30 - r) will be equals to the distance from this position to the other charge,
Tutorial Question 2
Answer
Main learning points
Answer
Main learning points
- Application of Electric Field strength equation into a field.
- Direction of the force on a charge due to electric field.
Tutorial Question 3
Answer
Main learning points
Answer
Main learning points
- Application of dynamics, use of Free-body diagram to understand charge is stationary because force due to electric field strength balances the weight on the charge.
Tutorial Question 4
Hint
Answer
Unlike the video presented answer, you should try solving the equation without taking into account the negative signs of the charges.
Main learning points
Hint
Answer
Unlike the video presented answer, you should try solving the equation without taking into account the negative signs of the charges.
Main learning points
- For a position with zero resultant electric field strength, the magnitude of opposing electric fields (2 different e-fields, in this question) are the same.
- Method of solution is very similar to that of question 1.
Tutorial Question 5
5a
5bc
Main learning points
5a
5bc
Main learning points
- Solving separately, the Electric field strength due to respective charges.
- The Electric field strength is then summed vectorially, as well as with the use of Pythagoras' theorem.
- It is paramount to understand the direction of the electric field vector before we can sum them up properly.
From qn 6 onwards,
we are dealing with scalars; electric potential and potential energy.
you must begin to include the negative signs from the charges into the equations now.
Tutorial Question 6
Answer
Main learning points
Answer
Main learning points
- Application of Work done and Conservation of Energy concepts.
- For the first time in tutorial, the Potential Energy equation for charges will be applied.
Tutorial Question 7
Answer
Main learning points
Answer
Main learning points
- Since potential is a scalar. One can use include the negative signs of the charges.
- Equate the potential of the two charges with r being the unknown distance away from one of the charges.
- Solve as in Question 1.
Tutorial Question 8
Answer
Main learning points
Answer
Main learning points
- For (a) solve as in question 4 and question 7.
- Understand that "work done" has a proper definition. Like G-field, work done is defined with its reference point at infinity.
Tutorial Question 19
19
19