Answer:
Explanation:
The expression which represent the first diffraction minima by a circular aperture is given by 
--------eqn 1
The angle through which the first minima is diffracted is given by 
---------eqn 2
As 
is very small so we can write 
So from eqn 1 and eqn 2 we can write
--------eqn 3
Here 
is the position of first maxima D is the distance of screen from the circular aperture d is the diameter of aperture
It is given that diameter of circular aperture is 14.7 cm so 
Now putting all these value in eqn 3
So you not only know<span> how fast it is going, but where it is going.</span>
Answer : (A) A charged object is brought near a neutral object without touching it.
Explanation:
Bodies can be charged by the method of conduction. By conduction the body acquires the same charge as on the charging body.
Charging the body can be understood by the following example of charging a paper cylinder by conduction. Make a paper cylinder by rolling a strip of paper on a pencil and then gently pulling out the pencil. Suspend the paper cylinder by a string tied to its center, now touch the paper cylinder with a glass rod rubbed with silk so it has a positive charge. Remove the class rod and the again bring it near to the paper cylinder.
The paper cylinder is repelled by the positively charged rod. And when you bring a negatively rubbed rod, next to the cylinder it will be attracted towards the rod. This means that the paper cylinder has acquired a positive charge as on the glass rod due to conduction.
Answer:
It’s b
Explanation:
Everyone else is wrong and I tried this and got it right
Answer:
The change in the charge on the positve plate when the Teflon is inserted is +2.5 nC.
Explanation:
- It can be showed that the capacitance of a parallel-plate capacitor, can be expresssed as follows:
- Where ε, is the dielectric constant of the material that fills the space between plates.
- When this space is filled with air, ε= ε₀ = 8,85*10⁻¹² F/m.
- At the same time, the capacitance of a capacitor, by definition, is as follows:
- If we insert a Teflon slab, in such a way that fills completely the gap between the plates, all other parameters being equal, if ε = 2*ε₀, this means that C₂ = 2* C₁. = 50 pF
- As V₂=V₁ (due to the capacitor remains connected to the same battery) the charge must be the double, so Q₂ = 2* Q₁ = 5 nC.
- So, the change in the charge of the positive plate is +2.5 nC.
