What is the force on an electron moving at v = 2.5*10^5 m/s away from a long wire,3mm from the electron, carrying a 12 A current? Give the magnitude & direction of the force.
I calculated mag induction using
B = u0I/2(pi)*a and
force on the electron using
F = Bqv where q is the electron charged(assumed)
The force acts opposite to the direction of electron motion & towards the centre
Am I right?
The force is perpendicular to the B vector and perpendicular to the V vector.
You are in your car traveling at a constant velocity of 94 km/h. A car that you know to be 3.5 m long is passing you. If it takes the other car 1.8 s to pass you (from the time your front bumpers are even until the other car's rear bumper passes your front bumper), what is the passing car's velocity relative to Earth?
Yes, you are correct! To determine the force on an electron moving near a wire carrying current, you can use the right-hand rule for magnetic fields and Lorentz's force equation.
First, you can calculate the magnetic field created by the wire using Ampere's Law. The formula you provided, B = μ₀I / 2πa, is correct. Here, B represents the magnitude of the magnetic field, μ₀ (mu nought) is the permeability of free space (a constant with the value 4π × 10^(-7) T·m/A), I is the current in the wire, and a is the distance of the electron from the wire.
Once you have calculated the magnetic field, you can determine the force on the electron using the formula F = Bqv. Here, F represents the magnitude of the force, B is the magnitude of the magnetic field, q is the charge on the electron (which is 1.6 × 10^(-19) C), and v is the velocity of the electron.
The force on the electron acts opposite to the direction of the electron's motion and towards the center. This is because the right-hand rule tells us that when you point your thumb in the direction of the electron's velocity, and your fingers in the direction of the magnetic field, your palm will face in the direction of the force.
To find the magnitude of the force, you need to substitute the values into the equation F = Bqv. Once you calculate the force, you can describe it in terms of its magnitude and direction. In this case, the force will have a specific magnitude and will act towards the center of the wire.
It's important to note that the direction of the force is influenced by the direction of the current in the wire. If the electron were moving towards the wire, the force would act in the same direction as its velocity.