# Physics

posted by .

A metal rod of length (L) moves with velocity (v), perpendicular to its length, in a magnetic field B, which is perpendicular to both the rod and its velocity. If the length of the rod is doubled, what happens to the electric field in the rod?

• Physics -

Since it is a conducting metal, there is no net E field. Negative charge accumulates at one end of the rod, while the rod moves, but there is also a magnetic force on electrons that opposes the field created by displaced electron charge.

If a closed circuit were formed, so that electrons were free to move in a current loop, the EMF (E-field times length) would double if the length of the rod doubled. The E-field would stay the same. I believe the value would be B * (V/c), but am not sure.

## Similar Questions

1. ### physics

A long, straight metal rod has a radius of 4.50 cm and a charge per unit length of 30.0 nC/m. Find the electric field at the following distances from the axis of the rod, where distances are measured perpendicular to the rod. a)3.00 …
2. ### physics

A horizontal rod with a length of 0.250 is mounted on a balance and carries a current. At the location of the rod a uniform horizontal magnetic field has a magnitude of 6.70×10−2 and direction perpendicular to the rod. The magnetic …
3. ### physics

A horizontal rod with a length of 0.250 is mounted on a balance and carries a current. At the location of the rod a uniform horizontal magnetic field has a magnitude of 6.70×10−2 and direction perpendicular to the rod. The magnetic …
4. ### physics

If a rod is moving at a velocity equal to 1/2 the speed of light parallel to its length, what will a stationary observer observe about its length?
5. ### Physics

If a rod is moving at a velocity equal to 1/2 the speed of light parallel to its length, what will a stationary observer observe about its length?
6. ### Physics

A long, straight metal rod has a radius of 6.00 cm and a charge per unit length of 36.0 nC/m. Find the electric field at the following distances from the axis of the rod, where distances are measured perpendicular to the rod. (a) 1.50 …
7. ### physics

A uniform rod is set up so that it can rotate about a perpendicular axis at one of its ends. The length and mass of the rod are 0.849 m and 1.17 kg. What constant-magnitude force acting at the other end of the rod perpendicularly both …
8. ### PHYSICS

A thin rod has a length of 0.339 m and rotates in a circle on a frictionless tabletop. The axis is perpendicular to the length of the rod at one of its ends. The rod has an angular velocity of 0.687 rad/s and a moment of inertia of …
9. ### PHYSICS

A thin rod has a length of 0.339 m and rotates in a circle on a frictionless tabletop. The axis is perpendicular to the length of the rod at one of its ends. The rod has an angular velocity of 0.687 rad/s and a moment of inertia of …
10. ### physics

A thin rod has a length of 0.25 m and rotates in a circle on a frictionless tabletop. The axis is perpendicular to the length of the rod at one of its ends. The rod has an angular velocity of 0.33 rad/s and a moment of inertia of 1.40 …

More Similar Questions