Answer:
The flux through the surface of the cube is 
Solution:
As per the question:
Edge of the cube, a = 8.0 cm = 
Volume Charge density, 
Now,
To calculate the electric flux:
(1)
where
= electric flux
= permittivity of free space
Volume Charge density for the given case is given by the formula:
(2)
Volume of cube, 
Thus

Thus from eqn (2), the total charge is given by:


Now, substitute the value of 'q' in eqn (1):

Look on this website http://hyperphysics.phy-astr.gsu.edu/hbase/phyopt/sinslit.html
Answer:
option B.
Explanation:
The correct answer is option B.
The phenomenon of the curtains to pull out of the window can be explained using Bernoulli's equation.
According to Bernoulli's Principle when the speed of the moving fluid increases the pressure within the fluid decrease.
When wind flows in the outside window the pressure outside window decreases and pressure inside the room is more so, the curtain moves outside because of low pressure.
The turns ratio is the factor that determines voltage andcurrent. In order to have the same current across the resistorin the primary as the resistor in the secondary, then:--N(p) = Primary turnsN(s) = Secondary turnsR(2) = Primary resistorR(1) = Secondary resistor--R(2)/R(1) = N(p)/N(s)R(2) = R(1)*(N(p)/N(s))--If arbitrary values are plugged in, you will see that this step up transformer will require 2x the resistance required in the secondary, R(1), to obtain the same current. Thus R(2) will be 1/2 the value of R(1). This is due to the stepped up voltage in the secondary.