Which is an example of colloid
1 answer:
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Answer & Explanation:
a)
Lenz's law states that the direction of induced electric current is always such that, it opposes the change in magnetic flux.
In a drop ride, the hub on which we sit and are hung to is an electromagnet and there are many such magnets mounted on the columns of the support. what happens is these electromagnets (in support) generate a repulsive magnetic field with respect to the field generated by the hub solenoids. this results in lift generation till the top of ride. reaching the top, the bar solenoids are at their maximum repulsive force. Then the solenoids in column are set current less means electric supply is cut off. this makes you fall under the effect of gravity. by the time you are half way down, column solenoids are turned on again. As the hub solenoid approaches every single electromagnet in supporting columns. Due to change in magnetic field (with respect to lenz's law) an opposing current induces further providing resistance to the fall, this continues until the ride comes to rest completely. This is how it works.
c) In addition, highly compressive springs, dampers, viscous dampers, etc. could be used in its place.
but the above listed cannot provide a differential braking,
have a limited lifecycle,
will provide resistance during lift also,
require higher maintenance
Answer:
The near point of an eye with power of +2 dopters, u' = - 50 cm
Given:
Power of a contact lens, P = +2.0 diopters
Solution:
To calculate the near point, we need to find the focal length of the lens which is given by:
Power, P =
where
f = focal length
Thus
f =
f = = + 0.5 m
The near point of the eye is the point distant such that the image formed at this point can be seen clearly by the eye.
Now, by using lens maker formula:
where
u = object distance = 25 cm = 0.25 m = near point of a normal eye
u' = image distance
Now,
Solving the above eqn, we get:
u' = - 0.5 m = - 50 cm