Answer:
e.)At twice the distance, the strength of the field is E/4.
Explanation:
The strength of the electric field at a certain distance from a point charge is given by:

where
k is the Coulomb's constant
Q is the charge
r is the distance from the point charge
In this problem, the distance from the point charge is doubled:
r' = 2r
So the new electric field strength is

so, at twice the distance the strength of the field is E/4.
I think the answer is letter B
Answer : The wavelength of photon is, 
Explanation : Given,
Energy of photon = 
Formula used :

As, 
So, 
where,
= frequency of photon
h = Planck's constant = 
= wavelength of photon = ?
c = speed of light = 
Now put all the given values in the above formula, we get:


Conversion used : 
Therefore, the wavelength of photon is, 
Answer:
0.0319 m³
Explanation:
Use ideal gas law:
PV = nRT
where P is pressure, V is volume, n is amount of gas, R is the gas constant, and T is temperature.
Since P, n, and R are held constant:
n₁ R / P₁ = n₂ R₂ / P₂
Which means:
V₁ / T₁ = V₂ / T₂
Plugging in:
0.0279 m³ / 280 K = V / 320 K
V = 0.0319 m³