1.which characteristic is common to all permanent magnets?

2. a proton enters a uniform magnetic field at a speed v . the magnetic field is oriented at an angle to the direction of the proton, and the strength of the field is b . which change or set of changes would double the magnitude of the force on the proton?

answer all three .

30 pts !

Two poles identified as North and South.

All magnets have North and South ends with magnetic field lines that leave the North end and loop around to the South end.

F =QBVsinΔ

As we can see from the formula, force is directly proportional to B so doubling the B will double the force.

Since field are perpendicular so sin90 = 1

             v = 4.6/10^4 / 5.2)

             v = 8846.15 m /s

1.

Two poles identified as North and South poles

Explanation:

All magnets must have different and opposite poles on either sides in which one pole must be south pole while other is North pole.

2.

Doubling B

Explanation:

Force on the moving charge is given by

so here we know that force is proportional to the product of q, v and B

so on doubling any one of the variable will increase the force to double.

3.

Explanation:

As electron passes undeviating so we can say that

the one with the highest speed

object 2 because all the other ones are wrong