15. A 150 resistance coil AB is connected across 240 V d. c supply Calculate the value of the resistance which when connected between the midpoint of AB and end A will carry current
of 0.8 A
Ans: 112.50​

As the distance from a magnet increases, what happens to the magnet force?

An athlete swings a ball, connected to the end of a chain, in a horizontal circle. the athlete is able to rotate the ball at the rate of 8.13 rev/s when the length of the chain is 0.600 m. when he increases the length to 0.900 m, he is able to rotate the ball only 6.04 rev/s. (a) which rate of rotation gives the greater speed for the ball? 6.04 rev/s 8.13 rev/s (b) what is the centripetal acceleration of the ball at 8.13 rev/s? m/s2 (c) what is the centripetal acceleration at 6.04 rev/s? m/s2

Which of the following forces require physical contact? tension air resistance friction magnetic force applied force