(a) 25lx
(b) 11.11lx
<u>Explanation:</u>
Illuminance is inversely proportional to the square of the distance.
So,

where, k is a constant
So,
(a)
If I = 100lx and r₂ = 2r Then,

Dividing both the equation we get

When the distance is doubled then the illumination reduces by one- fourth and becomes 25lx
(b)
If I = 100lx and r₂ = 3r Then,

Dividing equation 1 and 3 we get

When the distance is tripled then the illumination reduces by one- ninth and becomes 11.11lx
Answer:
B. Wave-like way with a pattern that is wave-like
Explanation:
The double slit experiment when performed with electromagnetic waves, gives a pattern of light lines and dark areas, equally spaced.
In the case of electrons we must use Broglie's duality principle that states that all things have the characteristics of particles and waves together. The characteristic observed in a given experiment depends on the type of experiment, using the relationship
p = h /λ
Where p is the amount of motion of the particle and λ the wavelength associated with this particle
In consequence of the previous one to the screen it should arrive as a wave with a wave type pattern
Let's review the answer.
A) False. The pattern is wave type
B) True. The whole process is with undulating characteristics
C) False. A wave arrives
D) False. A wave arrives
Answer:
student A or B
Explanation:
A common demonstration is to put a ringing alarm clock or bell in the bell jar, and when the vacuum is created, you can no longer hear the sound of the clock/bell.
The bell is connected to a lab pack or batteries and rung to show pupils it can be heard under normal circumstances. The bell jar is then connected to a vacuum pump using a vacuum plate (see Fig 2) and the air is removed from inside creating a near vacuum. The bell is then again rung. This time however, it cannot be heard.
Small low voltage buzzers can be used as a bell replacement for the bell and work in exactly the same way though teachers generally prefer bells as students may be able to see the hammer moving, proving that it is actually ringing even though they cannot hear it.
Some vacuum pumps are better than others at keeping a strong vacuum though if you cannot completely lose the sound, you will at least notice the volume decreasing.
Sound is simply a series of longitudinal waves travelling from the source, through the air to our ears. Without air present, these waves cannot form and therefore sound cannot be conveyed.
In a longitudinal wave the particles oscillate back and forth in the direction of the wave movement unlike transverse waves which like waves on the sea, single particles travel up and down and not in the direction of the wave.
Because you will not be able to create a perfect vacuum, you may still be able to hear the bell ring slightly. Vibrations from the ringing bell can also travel up to the bung in the bell jar which in turn may resonate the jar slightly. This means you may hear the bell ring, however strong the vacuum. To compensate for this, try to insulate the bell as much as possible from the bell jar. Hanging the bell using elastic cord means some of the vibrations will be absorbed by the cord and not be transferred to the bell jar.
Answer:
The force that happens between two particles with mass
Answer:
Explanation:
Given
there is fix Quantity of gas i.e. mass of gas is constant
From ideal gas Equation
PV=nRT
(a) volume always increases is not true as Pressure can also be increased .
(b)If Pressure is constant along with mass then as Temperature increases, Volume also increases.
(c)true , Product of Pressure and volume depends upon temperature thus it also increases with temperature.
(d)Density of gas may or may not increases
As density is 
volume may increase or decrease as temperature increase .
(e)false
as it clearly stated that quantity of fixed therefore there is no change in gas