The density of an iron bar depends upon the length of the bar true or false

The transfer of heat through the movement of a gas or liquid a. convection b. conduction c. radiation

Which of the following is an example of units for speed

Electromagnetic induction. a coil of wire contains n turns and has an electrical resistance r. the radius of each turn is a. initially, inside the coil there exists a uniform magnetic field of magnitude b0 parallel to the axis of the coil. the magnetic field is then reduced slowly. the current induced in the coil is i. how long does it take for the magnitude of the uniform field to drop to zero?