Given:
Lens.........diameter ...fl#
eyepiece...2cm............5
objective...40cm........15
focal length of eyepiece = 2*5 = 10cm
focal length of objective = 40*15 = 600cm
magnification = FL obj / FL eyp = 600/10 = 60x
Answer;
B. Fluorescent lamps operate at a higher temperature than incandescent lamps.
Explanation;
-A fluorescent lamp, is a type of electric light (lamp) that uses ultraviolet emitted by mercury vapor to excite a phosphor, which emits visible light.
-A fluorescent lamp produces less heat, thus, it is much more efficient. A fluorescent bulb can produce between 50 and 100 lumens per watt. This makes fluorescent bulbs four to six times more efficient than incandescent bulbs.
-Fluorescent lamps operate best around room temperature. At much lower or higher temperatures, efficacy decreases.
Atmospheric refraction is the deviation of light or other electromagnetic wave from a straight line as it passes through the atmosphere due to the variation in air density as a function of height. ... Refraction not only affects visible light rays, but all electromagnetic radiation, although in varying degrees.
So in short, the answer is D.
(My answer got deleted because it didnt explain which is dumb)
Answer:
a) 
b) 
Explanation:
From the question we are told that:
Density 
Velocity of wind 
Dimension of rectangle:50 cm wide and 90 cm
Drag coefficient 
a)
Generally the equation for Force is mathematically given by



Therefore Torque



b)
Generally the equation for torque due to weight is mathematically given by

Where

Therefore




We have
. So,
.
. So
.
Thus we can convert the units of the given quantity.
That is,
.
The quantity is converted to the required units.