Q. The top of a refrigerator has an area of 0.6 m2. The height of the refrigerator is 180 cm. What volume does the refrigerator occupy in cubic meters?

Q. A vacuum tube contains two axial cylinders. The potential difference between these cylinders is 500 V. Some electrons are released from the inner cylinder and are accelerated by the electric field toward the outer cylinder; a small current thereby travels through the tube. Suppose that a uniform magnetic field is set up parallel to the axis of the tube. This curves the trajectories of the electrons, and at a critical magnetic field, the electrons will no longer reach the outer cylinder, and the current ceases to flow. What is the kinetic energy of the electrons that hit the outer cylinder at a magnetic field just below the critical value?