Emf

A device called a homopolar generator has a metal disk that rotates in the presence of a magnetic field perpendicular tot he disk. Sliding contacts connect the axle and the outer surface of the disk to an external circuit. a) Explain why this device produces an emf between two contacts. Is this emf oscillating or constant? ...continues

Problem 3

Consider a generator. The loop in this generator rotates at an angular rate of w. The slip rings in this design ensure that the same leg of rotating loop is always connected to the same output terminal. Show that the potential difference between the output terminal is given by E=Eo cos(theta) (where theta =wt is the angle tha ...continues

Magnetism

A copper sulfate solution is placed in a container that contains coaxial cylindrical copper electrodes, as indicated in the picture. An electric field is created by connecting a battery across the electrodes as shown. A magnet field is created by immersing a magnet in the center of the solution as shown. Uncharged pollen g ...continues

Magnetism

A metal bar of mass m and length L slides without friction but with good electrical contact between two vertical metal posts. The bar and posts have negligible resistance. The posts are connected at the bottom by a resistor R. Assume the bar falls at constant speed v, and that there is a magnetic field coming out of the page. ...continues

Amplitude

1. The speed of sound waves in water (density 1.00 x 10 3 kg/m 3 ) is c=1480 m/s. [2] (a) What is the average intensity (in W/m 2 ) of a 1000 Hz sound wave in water if the displacement amplitude of the wave is 1.00 nm? (1 nm=10 -9 m). [2] (b) What is the ratio of pressure amplitude to displacement amplitude in this wave? ...continues

Amplitude

What are the amplitudes? See attached file for full problem description.

Tension, frequency

What is the tension and required mass?

Intensity

Find the intensity

Intensity

Find the minimum intensity

physics problems involving sound waves

physics questions The expression given below represents a transverse harmonic wave travelling along a string which is stretched along the horizontal x-axis. The expression yields the transverse wave displacement y in metres when x is entered in metres and the time t in seconds. For 1 mark each, answer the following q ...continues