Physics E&M

A slab of metal of volume V is made into a rod of length L. The rod carries current I when the electric field inside is E.Find the resistivity of the metal?

  1. 👍 0
  2. 👎 0
  3. 👁 353
  1. NVM again sorry I solved it.

    1. 👍 0
    2. 👎 0
  2. The cross sectional area of the rod is A = V/L. The resistance of the rod is
    R = (resistivity)*L/A
    = (resistivity)*L^2/V

    I = V/R = E*L/R,
    = E*L*V/(resistivity)*L^2
    = E*V/[resistivity*L]

    Solve for resisitivity

    1. 👍 0
    2. 👎 0
  3. The rod is now stretched so that its length is doubled. If the electric field remains the same, what is the new current I' in the rod? The answer to the first part was (EV)/(IL)

    1. 👍 0
    2. 👎 0
  4. If you double the length, the area decreases by a factor 1/2. In this case you keep the E field the same and not the voltage. Voltage doubles. Resistance increases by a factor of 4. the current therefore decreases by a factor of two.

    You can also see this from your formula. resistivity, E, and V are constant, so I is inversely proportional to L.

    1. 👍 0
    2. 👎 0
  5. Thank you phew I got it done on time

    1. 👍 0
    2. 👎 0
  6. A piece of copper is made into a rod with a square cross-section. The side of the square is 2.00 centimeters. The resistivity of copper is 1.7 \cdot 10^{-8} \Omega\cdot {\rm m}. An unknown electric field E, directed along the rod, creates a current of 12.0 amperes through the rod. Find the magnitude of E.

    1. 👍 0
    2. 👎 0
  7. kjlk

    1. 👍 0
    2. 👎 0
  8. 1)
    V = change in V
    E = electric field
    I = current
    L = length of rod
    A = square cross-section
    R = resistance

    given equations (from physic):

    E = V / L

    I = V / R

    R = rho * L /A

    by that:
    E*L =V
    IR =V

    R = rho *L /A

    EL = I * rho * L /A

    E = I * rho /A

    E = 12 * 1.7e-8 / (2/100)^2
    = 5.1e-4

    1. 👍 0
    2. 👎 0

Respond to this Question

First Name

Your Response

Similar Questions

  1. 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

  2. phy

    A slab of ice floats on a freshwater lake. What minimum volume must the slab have for a 50.0kg woman to be able to stand on it without getting her feet wet?

  3. AP Physics

    A uniform thin rod of length 0.3m and mass 3.5kg can rotate in a horizontal plane about a vertical axis through its center. The rod is at rest when a 3g bullet traveling in the horizontal plane of the rod is fired into one end of

  4. Physics

    A flat slab of styrofoam, with a density of 32 kg/m^3, floats on a lake. What is the minimum volume the slab must have so that a 42 kg boy can sit on the slab without it sinking?

  1. physics

    A uniform thin rod of length 0.55 m and mass 5.5 kg can rotate in a horizontal plane about a vertical axis through its center. The rod is a rest when a 3.0-g bullet traveling in the horizontal plane of the rod is fired into one

  2. physics

    A rod made from a particular alloy is heated from 24.5°C to the boiling point of water. Its length increases by 8.15 x 10-4m. The rod is then cooled from 24.5°C to the freezing point of water. By how much does the rod shrink?

  3. physics

    figure 3.1 shows a rectangular concrete slab of weight 18000N. It rests on a brick wall and is the roof of a bus shelter. The concrete slab is 3.0 m wide. The wall is 2.5 m from the front of the concrete slab and 0.50 m from the

  4. Physic please help!

    Two slabs with parallel faces are made from different types of glass. A ray of light travels through air and enters each slab at the same angle of incidence. Which slab has the greater index of refraction and why? slab A is a

  1. physics

    A metal rod is forced to move with constant velocity along two parallel metal rails, connected with a strip of metal at one end. A magnetic field of magnitude B = 0:350 T points out of the page. a) If the rails are separated by L

  2. Physics

    A rod made from insulating material carries a net charge, while a copper sphere is neutral. The rod and the sphere do not touch. (a) Is it possible for the rod and the sphere to attract one another? (b) Is it possible for the rod

  3. chemistry

    A metal rod has a mass of 17.62 g. A graduated cylinder contains 29.9 mL of water. The metal rod is added to the cylinder. The final water level in the cylinder is 36.1 mL. What is the density of the metal rod?

  4. Mathematics

    A cylindrical tube, open at both ends, is made of metal. The internal diameter of the tube is 10.4cm and its height is 25 cm. If thickness of the metal is 8mm everywhere, calculatd the volume of metal in the cylinder

You can view more similar questions or ask a new question.