i need some help in this conceptual questions..?
1)a beacon in lighthouse is to produce a parallel beam of light. The beacon consists of bulb be placed outside the focal point, at the focal point or inside the focal point of lense? State ur reason.
2)two people who were glasses were camping. One is near sighted and the other is farsighted. Whose glasses may be useful in a starting a fire with sun rays? Give ur reasoning
3)if we read for a long time our eyes become tired. When this happen it helps to stop reading and look at distance object. From the point of view of ciliary’s muscle why does this refresh the eyes?
4)which of the following are produce final image that are virtual.1)a projector 2)a camera 3)a magnifying glass 4)eyeglasses 5)a compound microscope 6)an astronomical telescope.
1. at the focal point of the lens or mirror. Because a parallel beam gets focused at the focal point.
2.The guy with farsight. His lenses are covex and produce a real focal spot where the sun rays conerge. for the near sighted person, the lesnses are cylindrical and will lead to beam divergence.
3. By shifting our focus from near to far off objets, the distance between the lens and the retina changes and this helps in relaxing the muscles. The distance reduces when we see distant objects and thus reduces the muscle tension.
4. Magnifying glass produces the virtual image since the object is between the lens and its focal spot.
40x2000x Compound Microscope
|
|
40x-2000x Professional Compound Microscope + 3MP Camera $405.00 |
|
|
New 3.6 Inch LCD 2.0MP Digital Color Camera For Compound Microscope $299.99 |
|
|
Trinocular Biological Vet Compound Lab Microscope w 3Mp USB Camera $479.00 |
|
|
New Binocular Compound Microscope 1000X + 1.3MP Camera $269.00 |
|
|
40X-2000X Siedentopf Trinocular Compound 3W LED Microscope + 1.3MP Camera $339.00 |
|
|
40X-2500X Infinity Kohler Laboratory Biological Compound Microscope + 5MP Camera $799.00 |
|
|
Premium Lab Research Trinocular Compound Microscope w 3488×2616 9.0MP Camera New $747.20 |
|
|
1600x New Binocular Compound Microscope + 1.3MP Camera $279.00 |
|
|
40X-2500X Infinity Kohler Laboratory Biological Compound Microscope + 3MP Camera $729.00 |
|
|
40X-2000X BIOLOGICAL COMPOUND MICROSCOPE + 5MP CAMERA $435.00 |
|
|
Bright/Darkfield Compound Microscope with Build-in 3MP Camera+Slides+Covers $469.90 |
|
|
40X-2000X Siedentopf Trinocular Compound 3W LED Microscope + 9MP Digital Camera $499.00 |
|
|
40X-2000X Siedentopf Trinocular Compound 3W LED Microscope + 9MP Digital Camera $499.00 |
|
|
40X-800X COMPOUND MICROSCOPE w/ USB DIGITAL CAMERA $179.98 |
|
|
40X-1600X Compound Microscope + 10MP Camera PC & Apple $695.00 |
|
|
50X-600X Zoom Compound Biological Microscope+USB Camera 640x480x Windows Vista 7 $319.90 |
|
|
40X-2000X Advanced Student Binocular Compound Microscope + USB2.0 Digital Camera $265.00 |
|
|
40x-1000x Biological Compound Microscope with 9M Camera $737.27 |
|
|
BIOLOGICAL 1.3MP CAMERA COMPOUND MICROSCOPE 40X-2000X $375.00 |
|
|
40X-2000X BIOLOGICAL COMPOUND MICROSCOPE + 1.3MP CAMERA $369.00 |
|
|
40X-1600X Trinocular Compound Microscope + 9MP Camera $499.98 |
|
|
Dry Darkfield/Bright Field Compound Microscope with 2MP Camera Windows 7 32/64 $419.90 |
|
|
Trinocular Compound Microscope 40X-2000X + 1.3MP Camera $379.00 |
|
|
Clinic Binocular Siedentopf Compound 40X-2000X Microscope+USB Camera Windows Mac $289.90 |
|
|
New 40X-2000X Trinocular Biological Compound LED Microscope + 5MP Digital Camera $438.00 |
|
|
Advanced Lab Research Compound Microscope Premium Lens Sturdy Base + 9MP Camera $688.88 |
|
|
40X-2000X BIOLOGICAL COMPOUND MICROSCOPE + USB CAMERA $349.00 |
|
|
40X-2500X Infinity Kohler Siedentopf Research Compound Microscope + 5MP Camera $850.00 |
|
|
High End Trinocular Microscope Compound 40-1600x Sturdy Base +5MP Digital Camera $588.88 |
|
|
40X-640X Infinity Plan Metallurgical Compound Microscope + 3MP Camera $1,443.00 |
|
|
New Lab Clinic Compound High Grade Microscope 40x-1600x +3MP USB Digital Camera $520.04 |
|
|
Trinocular Lab Compound Microscope Premium Lens Sturdy Base+1.3MP Digital Camera $510.21 |
|
|
40x-2000x Vet Optical Compound Microscope + USB Camera $269.98 |
|
|
40X-1600X TRINOCULAR COMPOUND MICROSCOPE + CAMERA + BOX $399.98 |
|
|
1600X TRINOCULAR COMPOUND MICROSCOPE + 1.3M CAMERA $399.98 |
|
|
40x-2000x Medical Student Compound Microscope + Camera $369.98 |
|
|
40X-2000X DOCTOR VET COMPOUND MICROSCOPE + 3MP CAMERA $395.00 |
|
|
40X-2000X Siedentopf Trinocular Compound 3W LED Microscope + 5MP Digital Camera $438.00 |
|
|
New 40X-2000X Trinocular Biological Compound LED Microscope + 3MP Digital Camera $375.00 |
|
|
40x-400x Student Compound Microscope + Digital Camera $149.98 |
|
|
Celestron 44102 400x Power Laboratory Biological Microscope $84.99 The Celestron(r) 400x Laboratory Biological Microscope comes with many scientific essentials such as a diaphragm and a condenser. Its efficient charm comes in its power and precision, with 3 different objective lenses and a monocular, adjustable head that rotates from 0 to 60 degrees for comfortable viewing…. |
|
|
AmScope Nikon SLR / D-SLR Camera Adapter for Microscopes – Microscope Adapter $78.75 This is a brand new Nikon SLR/DSLR Camera adapter for microscopes. Coming with 23.2mm, 30mm and C-mount adapters, it fits almost all kinds of microscopes including compound and stereo microscopes. Its retail value is $350…. |
|
|
AmScope 40X-1000X Cordless LED Student Compound Microscope with Coarse & Fine Focus + Digital Imager $129.98 This microscope with a digital imager (digital camera) is designed for students to learn science, offering five magnification settings, 40X, 100X, 250X, 400X and 1000X. It comes with a 640×480 pixel USB2.0 imager, full optical glass elements, all metal framework, 360° rotatable monocular head, coarse & fine focus, and the LED illumination system that uses either wall-power (adapter included) or t… |
|
|
Nikon Premier LX-L 8×20 Binoculars $758.95 Traditionally, an 8×20 binocular is perfectly suited for theater and stadium use. Extraordinarily compact, it provides ample magnification with a reduced field of view so you can Focus on Character and action details. Of course, it’s really lightweight and easy to carry around. The Nikon Premier LX offers superior optics and all-weather protection so you can use it as a very compact birding and fi… |