Question

- points MI4 13.3034 Three bulbs The figure is a top view of a circuit containing three identical light bulbs (the rest of the circuit including the batteries is not shown). The direction of the North pole is toward the right. The connecting wires are made of copper. 3: (a) The compass is placed on top of the wire, and it deflects 20 degrees away from north as shown (the wire is underneath the compass). Which of the following statements about the magnetic field caused by the electrons moving at location P, are true? There may be more than one. Electrons are moving to the right. At the location of the compass, the magnetic field due to the conventional current points toward the top of the page. Electrons are moving to the left. At the location of the compass, the magnetic field due to the conventional current points toward the bottom of the page. (b) In the steady state, 2 x 1018 electrons pass location P, every second. How many electrons pass location P2 every second? (c) Which relation describes the relative brightnesses of bulbs B, B2, and B3? B: > B2 =B3 B2 = B3 > B B1-B2 = B3 B3 > B, B2 B3 <B (d) There are 6.3 x 1028 mobile electrons per cubic meter in tungsten. The cross-sectional area of the tungsten filament in bulb B1 is 0.01 mm2 (1 mm2 = 1 x 10-6 m2). The electron mobility in hot tungsten is 1.2 x 10-4 (m/s)/(N/C). Calculate the magnitude of the electric field inside the tungsten filament in bulb B. IV/m Additional Materials

Answer 1

@ It is given compass is placed on the top of the wire & it is deleted 20° away from north. It means that magnetic field at this location due to flow of elecoms must be pointed towards the top of the page. AS direction of the magnetic field existing on the top of the page decrons flow at a given location P, towards right ① 200 1018 108 elorrmal electons/s 2 = ② since bulbs 2&3 are identical, the arrent coually blw bulbs de 3. current divides the bulb equally between the bulbs 283, brightness of 2&3 are equal r [B2 =B3) & Bil option or î : a xio's 2 E- AU 6.3x1028 x 1x 168 x 1.2x104 E = 26.45 N/C LON V/m.