Two parallel horizontal wires run from left to right across

Two parallel, horizontal wires run from left to right across the page. Each wire carries a current of 1.5 A. The current flows in the same direction, in the two wires. The forces on the two wires are one to the right and one to the left. zero attractive repulsive one in and one out of the page both in the same direction A horizontal current carrying wire (in the plane of the page) is placed in a magnetic field as shown below. The magnetic force at point A on the w ire is to the right downwards into the page upwards to the left out of the page Five devices (i-v) are listed below. Electric Motor, capacitor, potential divider, anemometer Hall Probe. Which of the devices uses Faraday\'s Law to explain its operation? A solenoid of length of 0.50m and cross-section area of 300cm^2 contains 1500 turns of wire carrying 2.5 A of current. What is the magnetic field generated at the center of the solenoid 3.2 Times 10^-3 T. 6.3 Times 10^-3 T 9.5 Times 10^-3 T 11.4 Times 10^-3 T 12.6 Times 10^-3 T 18.9 Times 10^-3 T

Solution

i)

answer C) attractive

Two current carrying wires with current in same directions attract each other

ii)

answer : B) downwards

the direction of the magnetic force is given by Right Hand Thumb rule

iii)

ANSWER : B) i and iv

In electric motor the change in magnetic field induces a voltage thus the voltage is generated

In anemometer, the mechanical movement of the cups causes change in the magnetic field causing the flow of electric current to measure the wind velocity

iv)

L = 0.5 m

A = 300 cm2

N = 1500

I = 2.5 A

magnetic field generated at the center of solenoid is given by:

B = u*N*I/L

= 1.26*10^-6*1500*2.5/(0.5)

= 9.5*10^-3 T <------- option C