Answer:
I₂ = I₀ 1/4
Explanation:
For this exercise we use the definition of intensity which is the power per unit area
I = P / A
The emitted power is constant, so
P = I A
We can write this equation for the start and end point with index 2
I₀ A₀ = I₂ A₂
I₂ = I₀ A₀ / A₂
The spot area is the area of the circle
A₀ = π r₀²
We substitute
I₂ = I₀ r₀² / r₂²
It indicates that the radius of the spot is twice the initial radius
r₂ = 2 r₀
I₂ = I₀ (r₀ / 2 r₀)²
I₂ = I₀ 1/4
Answer:
The number of turns in the secondary coil is 28.
Explanation:
Given that,
Input voltage given to the transformer, ![V_p=111\ V](https://tex.z-dn.net/?f=V_p%3D111%5C%20V)
Output voltage supplied to the video game, ![V_s=9\ V](https://tex.z-dn.net/?f=V_s%3D9%5C%20V)
Number of turns in the primary coil, ![N_p=340](https://tex.z-dn.net/?f=N_p%3D340)
We need to find the number of turns in its secondary coil. We know that the transformer equation is given by :
![\dfrac{V_s}{V_p}=\dfrac{N_s}{N_p}\\\\N_s=\dfrac{V_s}{V_p}\times N_p\\\\N_s=\dfrac{9}{111}\times 340\\\\N_s=27.56](https://tex.z-dn.net/?f=%5Cdfrac%7BV_s%7D%7BV_p%7D%3D%5Cdfrac%7BN_s%7D%7BN_p%7D%5C%5C%5C%5CN_s%3D%5Cdfrac%7BV_s%7D%7BV_p%7D%5Ctimes%20N_p%5C%5C%5C%5CN_s%3D%5Cdfrac%7B9%7D%7B111%7D%5Ctimes%20340%5C%5C%5C%5CN_s%3D27.56)
or
![N_s=28](https://tex.z-dn.net/?f=N_s%3D28)
So, the number of turns in the secondary coil is 28.
Answer:
Explanation:
Considering it to be True or False Statements
(a)True ,
when Potential Energy of the system is zero then force on the object is zero
![F=-\frac{\mathrm{d} U}{\mathrm{d} x}](https://tex.z-dn.net/?f=F%3D-%5Cfrac%7B%5Cmathrm%7Bd%7D%20U%7D%7B%5Cmathrm%7Bd%7D%20x%7D)
![F=0](https://tex.z-dn.net/?f=F%3D0)
(b)True
When ball is thrown upward it faces air resistance of greater magnitude because of the high speed of ball. while on returning the speed of ball gradually increase therefore it take more time to reach same spot
(c)True
Change in gravitational Potential Energy of two balls will be different as gravitational Potential Energy depends on the distance of object from datum.
Also Potential Energy can also be negative as it depends on reference
(d)False
if Force on object is zero then Potential Energy is constant not zero
![F=0](https://tex.z-dn.net/?f=F%3D0)
i.e.![\frac{\mathrm{d} U}{\mathrm{d} x}=0](https://tex.z-dn.net/?f=%5Cfrac%7B%5Cmathrm%7Bd%7D%20U%7D%7B%5Cmathrm%7Bd%7D%20x%7D%3D0)