Solve Basic Electricity and Magnetism Questions - No Calculations Needed

In summary, the conversation is about basic questions regarding physics and the use of relevant equations to solve problems. The participants also discuss the use of the right hand rule and why the magnetic field does not do work. They also mention the importance of understanding the concepts and equations rather than just memorizing them.
  • #1
compscier
6
0
Yes, yes I know about the template, but these questions are so basic that I don't really know what I can show as work... Sometimes all I need for help is the relevant equation itself -.- So please don't delete or hate. Thanks!


2. http://tinyimage.net/images/50136173150204648365.png
The answer is A and A explain please?


4. http://tinyimage.net/images/85261815545593376175.png
umm the answer is A, and I have no idea what to use...

5. http://tinyimage.net/images/61071039590674115839.png
WHAT WHY IS ISN'T IT 2uJ? THIS DEFIES PHYSICS WAHHH joking lol

6. http://tinyimage.net/images/49749004950847017201.png
I'm guessing you use kirchhoffs law for this...

7. http://tinyimage.net/images/00194558680517153372.png
so i get why 66 is B, but why is 67 B as well?? shouldn't the graph just be the formula shown in 66?

Any help would be appreciated
 
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  • #2


compscier said:
2. http://tinyimage.net/images/50136173150204648365.png
The answer is A and A explain please?

This really should not be answered, it is so basic. Just use coulomb's law

compscier said:
3. How do you know which formula to use for the energy stored in the capacitor (you know there's 1/2QV and 1/2V^2C...) like for number 61 in http://tinyimage.net/images/82840419860896498375.png

It depends upon the ease of use. In 61 the capacitors are in series so q will be constant. Hence best would be 1/2Q2/C ---> You missed out on this formula
 
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  • #3


compscier said:
1. a charged particle is projected parallel to a uniform to a magnetic field, the resulting path is a straight line parallel to the field... why? doesn't the right hand rule apply here

What does the right hand rule say?
 
  • #4


ashishsinghal said:
This really should not be answered, it is so basic. Just use coulomb's law



It depends upon the ease of use. In 61 the capacitors are in series so q will be constant. Hence best would be 1/2Q2/C ---> You missed out on this formula

1. hmm is electric potential a scalar?

2. So wait, what's wrong here:
1/2*V^2*C=1/2*6*6*(1/(1/6+1/6+1/6))=1/2*36*2=18?
 
  • #5


Abdul Quadeer said:
What does the right hand rule say?


ahh is it because the angles between velocity of the particle and magnetic field is 0, thus eliminating the force?
 
  • #6


compscier said:
ahh is it because the angles between velocity of the particle and magnetic field is 0, thus eliminating the force?

Yes your are right.
It is convenient to use right hand rule to find out the direction of force acting on the particle when the magnetic field vector and velocity vector are perpendicular. You may answer this question by using the equation F=q(vxB)
 
  • #7


compscier said:
1. hmm is electric potential a scalar?

2. So wait, what's wrong here:
1/2*V^2*C=1/2*6*6*(1/(1/6+1/6+1/6))=1/2*36*2=18?

This will give you net energy. BTW 1/2*36*2=36
 
  • #8


hmm help me on the other ones please?
 
  • #9


Can't answer 5th.
For the 6th: just do it - nike
For the 7th: you need to tell why are you not getting B for 67
 
  • #10


compscier said:
5. http://tinyimage.net/images/61071039590674115839.png
WHAT WHY IS ISN'T IT 2uJ? THIS DEFIES PHYSICS WAHHH joking lol

2uJ is the work done by the Electric field. The magnetic field does no work.
 
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  • #11


Abdul Quadeer said:
2uJ is the work done by the Electric field. The magnetic field does no work.

Yeah, that is the point. Since force is perpendicular to the velocity F.ds =0.
 

1. What is the difference between electricity and magnetism?

Electricity and magnetism are both forms of energy, but they have different characteristics. Electricity is the flow of electrically charged particles, while magnetism is the force exerted by magnetic fields. In other words, electricity is a form of energy and magnetism is a force.

2. How does electricity flow through a circuit?

Electricity flows through a circuit in a closed loop, starting at the power source (battery or outlet) and traveling through wires to the device being powered. The electrons in the circuit flow from the negative terminal of the power source to the positive terminal, creating a flow of electricity.

3. What is the relationship between electricity and magnetism?

Electricity and magnetism are closely related and are often referred to as electromagnetism. When an electric current flows through a wire, it creates a magnetic field around the wire. Likewise, a changing magnetic field can induce an electric current in a nearby wire. This relationship is the basis for many devices, such as generators and motors.

4. How do magnets work?

Magnets have two poles, a north pole and a south pole, and they have the ability to attract or repel objects that have opposite or like magnetic poles. This is due to the alignment of the magnetic fields of the magnets. When two magnets are brought together, the north pole of one magnet will attract the south pole of the other magnet, while the north pole of one magnet will repel the north pole of the other magnet.

5. Can electricity and magnetism be seen?

No, electricity and magnetism cannot be seen with the naked eye. However, their effects can be observed in various ways. For example, we can see the effects of electricity when we turn on a light bulb or use electronics. We can also see the effects of magnetism when we use compasses or see objects being attracted or repelled by a magnet.

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