A toroid having a square cross section, 5.49 cm on a side, and an inner radius of 18.1 cm has 450 turns and carries a current of 0.859 A. (It is made up of a square solenoid instead of round one bent into a doughnut shape.) What is the magnitude of the magnetic field inside the toroid at (a) the inner radius and (b) the outer radius

69. air frictionthe velocity of the satellitea. decreases b. increases c. sometimes increases sometimedecreases d. no effect at all70. the unit of gravitational potential energy isa.jouté b.watt c. newtond.pascal71. which of the following is not influenced by a magneta. cobalt b.copper c.irond. nickel72. one joule of work done in one second by unit positive chargea.1 watt b.1 volt c.1 js d. none73. the most deviated colour of light after passing through a prisea. violet b.red c. green d.yellow4. a coin is placed below a beaker fill with water upto 12 cm isdisplaced by water isa. 9cm b.6cmс.3cmd.7cm