Physics 2 Answer as many as you know please 12. A pair of parallel wires are eac
ID: 306673 • Letter: P
Question
Physics 2
Answer as many as you know please
12. A pair of parallel wires are each carrying currents of 10 A in opposite directions. The wires are separated by a perpendicular distance of 0.5 cm. The force per unit length between the wires is: A) 0.004 N/m, attraction B) 0.004 N/m, repulsiorn C) 0.001 N/m, repulsion D) 0.001 N/m, attraction E) zero 13. In the sketch (not to scale) a long straight wire carries a current I, upward in the plane of the page. A square frame is also in the plane of the page and to the right of the straight wire. It carries a counterclockwise current of I2 and its side is parallel to the wire. Which of the following correctly describes the net force on the frame of wire: A) The frame is repelled by the wire. B) The frame is attracted to the wire. C) The net force on the wire frame is zero, but the net torque attempts to rotate it around a horizontal axis. D) The net force and torque on the wire frame are both zero. E) The net torque on the wire frame attempts to rotate it counterclockwise 14. A circular loop of wire with radius R = 2.0 m carries current of I = 7.5 A as shown in the sketch. The wire lies in the plane of the paper, with the long, straight parts along the x-axis. Find the magnitude and direction of the magnetic field created at the center of the loop. A) 1.38x10 T., into the page B) 4.97x10s T., into the page C) 3.77x10 T., out of the page D) 3.11x10 T., out of the page E) 3.11x106 T., into the page P Page 5Explanation / Answer
12.
F= k*2*(i1)(i2)/r
= 9*10^9*2* 100/0.005
= 0.004 N/m, force is ruplsive in nature
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13.
We can find the direction of force on side closest to the wire by Fleming's left hand rule and in the particluar case it is along +x axis.
And firce on the side opposite to the sode discussed above is directed to the -- axis,
Now net force given by these two vector can be find by vector sum of these two wires,
As the force on side closest to the wire is more than the opposite side, hence net force must be along +x axis.
So loop is repelled by the wire.
Option(a ) is correct.
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Magnetic field at the center of loop
B= (uo/4*pi)* 2*pi* i/r + (uo/4*pi)* 2*i/r
= 10^-7*2*3.14* 1.75/2 +10^-7* 2* 7.5/2
= 3.11*10^-6 , directed into the page
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