2 marks) Use Gauss’ law to find the E-field outside of a long straight wire.

A long straight wire of circular cross section of radius a carries asteady current I. The current is uniformly distributed across itscross section. The ratio of the magnitudes of magnetic field at apoint distant a/2 above the surface of wire to that at a point distanta/2 below its surface is(i) 4 :1(ii) 1:1(iii) 4: 3(iv) 3 :4

1. Ll___________________ 2. It is the electric field multiplied by the distance.___________________ 3. An emf induced by the motion of the conductor across the magnetic field.___________________ 4. It is the electric field E multiplied by the length.___________________ 5. States that the induced emf in a circuit is equal to the time rate of change of the magnetic flux through it.___________________ 6. A non-conservative field in the loop equal to the emf divided by the circumference of the loop.___________________ 7. Consists of coils of conductors that receive a voltage and produce magnetic flux.___________________ 8. They are electrical connections that are used to transfer power to and fro from the rotor of an AC generator.___________________ 9. It converts mechanical energy into electrical energy.___________________10. Force that makes the free charges in the rod moves, at the upper end creating an excess of positive charge and of a negative charge at the lower end.___________________11. Unit of a magnetic field.___________________12. A current measuring device.___________________13. Current caused by changing magnetic field in the circuit.___________________14. Equation of emf when v is not perpendicular to the field B.

A cylindrical wire of radius 0.5 mm and conductivity 5 × 107 S/m is subjected to an electric field of 10 mV/m. The expected value of current in the wire will be x3π mA. The value of x is ____.

Electrical resistivity of a given metallic wire depends uponA its length. B its thickness. C nature of the material. D its shape.

Two long parallel wires are at a distance of 4 cm4 cm. They carry currents I𝐼 and 3I3𝐼 in same direction. Where will the field produced by both wires be zero from current I𝐼?