An important principle that allows fiber optics to work is
In optics, normal means
The law of reflection applies to
When light passes from air to glass
After passing through a the lens of a camera or the eye, the focal point is defined as where the rays meet.
Mr. Smith is gazing at something as shown in the figure to the left. Suppose he does not refocus, but attempts to stare at the star shown in the figures below. Which diagram depicts how the rays from the star would travel if he does not refocus?
The focal point is where
When light passes from glass to air
Which lens has the shorter focal length?
If this represents the eye looking at an object, where is this object?
A cosmic ray alpha particle encounters Earth's magnetic field at right angles to a field of 23.7 μT. The kinetic energy is 438 keV. What is the radius of particle's orbit?
Two parallel wires are 7.3 meters long and are separated by 6.7 mm. What is the force if both wires carry a current of 9.3 amps?
Blood is flowing at an average rate of 16.5 cm/s in an artery that has an inner diameter of 4.7 mm. What is the voltage across a hall probe placed across the inner diameter of the artery if the perpendicular magnetic field is 0.15 Tesla?
An electron tube on Earth's surface is oriented horizontally towards magnetic north. The electron is traveling at 0.06c, and Earth's magnetic field makes an angle of 45.5 degrees with respect to the horizontal. To counter the magnetic force, a voltage is applied between two large parallel plates that are 45 mm apart. What must be the applied voltage if the magnetic field is 36μT?
Two orbiting satellites are orbiting at a speed of 58 km/s perpendicular to a magnetic field of 46 μT. They are connected by a cable that is 22 km long. A voltmeter is attached between a satellite and one end of the cable. The voltmeter's internal impedance far exceeds the net resistance through the ionosphere that completes the circuit. What is the measured voltage?
Referring to the previous question, the voltmeter is replaced with by a 45.8 kΩ resistor, causing the the voltage falls to 78% its original value. What is the effective internal impedance of the ionospheric plasma?
Referring to the previous problem, what power is developed by the 45.8 kΩ resistor?
An loop of wire with 31 turns has a radius of 0.9 meters, and is oriented with its axis parallel to a magetic field of 0.83 Tesla. What is the induced voltage if this field is reduced to 35% of its original value in 1.7 seconds?