Electromagnetism

Question 1

electromagnetism?
magnetism?
magnetic field?
what can create a magentic field?

Question 2

gravitational, electric & magentic field exert force on?

Question 3

key distinction between magentic & electric field lines?
where is magetic field strongest?

only 1

Answer 3

at the poles

Question 4

properties of magnetic field lines?

Answer 4

• vector
• density of magnetic field
• never cross
• closed loops
• north/south pole
• like/unlike poles

Question 5

• magentic field due to curent in a long straight wire?
• what happens if we reverse the direction of current?
• the direction of magnetic force depends on the direction of?
• the B lasts as long as?

Question 6

how to find the direction of magentic field?

Question 7

derivation for magnetic force?
how does this force arise?

Question 8

magnetic force is perpendicular to?
max magentic force?
minimum?
when will current carrying conductor not experiance force?

Question 9

fleming left hand rule?
it is used to find the direction of the?

Answer 9

direction of the magnetic force experienced by conductor (thumb)

Question 10

define flux density? aka? formula flux density? explain the formula?
SI unit?
magnetic field is scalar/vector?

Question 11

define 1 tesla?

Question 12

on what conditions the moving charge experiance magnetic force?
Q: In what direction does magnetic force act?
Q: What does θ represent?
what if its 90 180 or 0?

Answer 12

2 conditions
A: Perpendicular (90°) to both velocity (v) & magnetic field (B).
A: The angle between velocity (v) and magnetic field (B).

Question 13

force experianced by positive point charge?
negative charge?
when will the force be max and min

Question 14

magnitude of magnetic force acting on +ve point charge is product of?
megnetic force on +ve charge formula? -ve charge?
when is the force max? and min?
parallel and anti parallel?
if theta is other than 180 90 & 0 then? fig. 12.10

Question 15

direction of force experianced by moving charge?
for positive & negative charge?
what is used to determine it?

Question 16

velocity selector method?
derive formula for velocity?
which particles will pass out?
slower/faster than the speed?

Question 16

motion of charged particle moving in a uniform magnetic field? derive the formula?
cyclotron frequency of charged particle?

Question 17

lorentz force? equation?
diagram for velocity selector?

Question 18

magnetic field due to current carrying straight conductor?
strength of magnetic field depend upon? formula? values?

Question 19

magnetic field due to current carrying flat circular coil? formula for magnetic field? diagram?

Question 20

magnetic field due to current carrying solenoid?
what is solenoid?
magnetic field of solenoid?
north & south pole depend on?
where is field strong & uniform?
formula? explain it?
how to find the north pole of the solenoid?

Question 21

what are ferrous materials?
what if a ferrous material is placed inside the solenoid?
what if wire of solenoid is tightly wound on the iron core?
what is electromagnet?
relative permeability of iron is? formula?
common ferrous materials used in core?

Question 22

What happens when two parallel wires carry current in the same direction?

What does each current-carrying wire produce?

How does each wire interact with the other wire’s magnetic field?

In which direction does the magnetic force act on a current-carrying wire?

What is the net magnetic field between two wires carrying current in the same direction?

How is the magnetic field on the outside of two wires carrying current in the same direction?

Why do two wires carrying current in the same direction attract?

Answer 22

They attract each other due to magnetic force.

A circular magnetic field around itself.

Each wire feels the magnetic field of the other and experiences a force.

Perpendicular to both the current and magnetic field (𝐹 = I L × B).

Weak, because the fields are opposite and partially cancel.

Stronger, because the fields add up outside the wires.

Magnetic force pushes them from strong field (outside) → weak field (between wires).

Question 22

right hand rule III for a solenoid? used to find?

Question 23

What is the neutral point between two wires? Where is the neutral point if the currents are equal? Where is the neutral point if currents are unequal?

Answer 23

The point where magnetic fields are equal and opposite, so net field = 0. Midway between the wires. Closer to the wire with smaller current, because stronger current creates stronger field.

Question 24

What happens when two parallel wires carry currents in opposite directions? How are the magnetic fields between wires with opposite currents? How is the magnetic field outside wires with opposite currents? Why do wires with opposite currents repel each other? magnetic force acts on current carrying conductor from stronger to weaker magentic field region. T/F

Answer 24

They repel each other due to magnetic force. The fields are in same direction, so strong between wires. Fields oppose each other, so weak outside. Magnetic force pushes them from strong field (between wires) → weak field (outside).

Question 25

derive formula for finding force exerted by first wire on the second wire? formula for magnetic field of 1st & 2nd wire?

Question 26

magnetic flux? symbol? mathematically? magnitude? unit? 1 unit=?

Question 27

how do we get max flux? minimum or zero flux?

Question 28

how do we find flux if a curved surface is placed in non-uniform magnetic field? formula

Question 29

magnetic flux density? aka? symbol? unit?

Answer 29

magnetic induction

Question 30

magnetic flux linkage? commonly used for? how can magnetic flux of single turn be increased? formula? symbol? unit?

Question 31

define EM induction? basic requirement for EM induction? state Faraday's law? derive equation? used to determine?

Question 32

induced emf **always** opposes? direction of induced emf? explain?

Answer 32

change in magnetic flux

Question 33

what does faraday's law describe? example?

Question 34

experiment: bar magnet & coil connected to a senstitive galvanometer? cases?

Question 35

experiment: coil is rotated in a magnetic field?

Question 36

emf induced by changing magnetic field?

Question 37

basic principle of the the working of a transformer?

Question 38

cause of induced emf? can constant magnetic flux produce emf? magnitude of induced emf depends upon? induced emf is independent of? & depends on? induced current depends on? formula?

Question 39

factors affecting the magnitude of the induced emf?

Question 40

state Lenz's law? condition for its application

Question 41

explanation of Lenz's law?

Question 42

explanation of Lenz's law? what is it determined by it?

Question 43

how is Lenz's law in accordance with the law of conservation of energy?

Question 44

how to find the direction of induced current?

Answer 44

fleming right hand rule

Question 45

seismometer? what is it used for? look like?

Question 46

working seismometer?