General shit

Question 1

when drawing diagrams of magnetic field lines and shit like that, the dots and crosses don’t just symbolise magnetic field lines. They could also represent the direction of current, force or any other representation, as long as they are labelled.

Answer 1

Facts

Question 2

Into the page and out of the page are dependent on dots and crosses.

Up and down the page are dependent on 2D figures (where there’s no dots and crosses and just arrows of motion)

Answer 2

Real

Question 3

Orbital velocity is derived through?

Answer 3

Orbital velocity is derived through centripetal force. Since in planetary motion, gravitational force is equivalent to centripetal force, we equate the two values together and finally, this will be give you the orbital velocity.

Question 4

Escape velocity is derived through the Law of conservation of Energy, where the GPE is equal to the kinetic energy. Therefore equate the formulas where GPE in planetary motion is -GMmr. Therefore the formula should consider the mass of the planet, not the object in motion. Therefore, mass of satellite does not matter

Answer 4

Therefore formula for escape velocity is

V (esc) = Square root of√(2GM / r)

Therefore, everything is inside the square root and the inside bit is 2GM / r

Question 5

a voltmeter has high resistance, to prevent current from passing through it while it measures the voltage difference between two points. Therefore, always consider the voltmeter when it comes to analysing a circuit setup.

Answer 5

Alright I will do that.

Btw, the resistance for an ammeter is low, because the whole point is to measure the curretn

Question 6

Lenz’s law is a consequence of conservation of energy applied to electromagnetic induction. It was formulated by Heinrich Lenz in 1833. While Faraday’s law tells us the magnitude of the EMF produced, Lenz’s law tells us the direction that current will flow. It states that the direction is always such that it will oppose the change in flux which produced it. This means that any magnetic field produced by an induced current will be in the opposite direction to the change in the original field.

Answer 6

for real

Question 7

What is electromagnetic induction?

Answer 7

Electromagnetic induction is essentially Faraday’s Law.

The creation of emf when a conductor with its own existing magnetic field interacts with an external magnetic field, which induces an emf/ back emf

Question 7

How can we identify a situation that uses Lenz’s Law?

Answer 7

Identify any situation where there is a change in magnetic flux.

Any problem which has a conductor experiencing a change in flux.

Question 8

What are prac examples of changing magnetic flux?

Answer 8

Magnetic flux changes when you pass a magnet through a conductor for example, since this will produce a current due to the electrons (delocalised) being dislocated and forced to move.

Question 9

What is the difference between current and emf?

Answer 9

Current is the flow of electrical charge per unit time. Therefore it is the rate at which electrical charge flows.

whereas electromotive force (Emf) is the potential difference/force required to cause current to flow