Two long thin conducting tubes are concentric with each other. The outer tube has a radius R and has a current I while the inner tube has a radius R/4. To cancel the field at points r > R, the inner tube must have a current a.) running parallel to I of magnitude I/4 b.) running parallel to I of magnitude I c.) running antiparallel to I of magnitude 1/4 d.) running antiparallel to I of magnitude I

Two long, straight wires are parallel and 15 cm apart. One carries a current of 2.8 A, the other a current of 5.6 A. (a) If the two currents flow in opposite directions, what is the magnitude (in N/m) and direction of the force per unit length of one wire on the other? magnitude N/m direction ---Select--- (b) What is the magnitude (in N/m) and direction of the force per unit length if the currents flow in the same direction? magnitude N/m direction ---Select---

An accelerating voltage of 2.36 x 10³ V is applied to an electron gun, producing a beam of electrons originally traveling horizontally north in vacuum toward the center of a viewing screen 37.9 cm away. (a) What is the magnitude of the deflection on the screen caused by the Earth's gravitational field? (b) What is the direction of the deflection on the screen caused by the Earth's gravitational field? up down east west (c) What is the magnitude of the deflection on the screen caused by the vertical component of the Earth's magnetic field, taken as 20.0 μT down? east m (d) What is the direction of the deflection on the screen caused by the vertical component of the Earth's magnetic field, taken as 20.0 µT down? north south west mm (e) Does an electron in this vertical magnetic field move as a projectile, with constant vector acceleration perpendicular to a constant northward component of velocity? Yes No O No (f) Is it a good approximation to assume it has this projectile motion? Yes…

Question 1: A) Dinesh studying rail guns has been suggested for launching projectiles into space without chemical rockets. A tabletop model rail gun (Figure 1.) consists of two long, parallel, horizontal rails, l= 6.80 cm apart, bridged by a bar of mass m= 8.00 g that is free to slide without friction. The rails and bar have low electric resistance, and the current is limited to a constant I = 42.0 A by a power supply that is far to the left of the figure, so it has no magnetic effect on the bar. Figure 1 shows the bar at rest at the midpoint of the rails at the moment the current is established. He wishes to find the speed with which the bar leaves the rails after being released from the midpoint of the rails (Hint: you need to draw the figure). (Mo = 4π × 10-¹T.) Jg x V₁ = = 0 m d Figure 1. (i) Find the magnitude of the magnetic field at a distance of 1.85 cm from a single long wire carrying a current of 2.40 A. (ii) For purposes of evaluating the magnetic field, model the rails as…