Answer:
4.4×10⁻⁷ Coulomb
Explanation:
V = Voltage = 5.8 kV
d = Potential distance = 2.8 mm = 0.0028 m
A = Area = 0.3×0.08 = 0.024 m²
ε₀ = permittivity constant in a Vacuum= 8.85×10⁻¹² F/m
Magnitude of charge transferred between a carpet and a shoe is 4.4×10⁻⁷ Coulomb.
Answer:
B. +m
Explanation:
The magnification of an image is defined as the ratio between the size of the image and of the object:
where we have
y' = size of the image
y = size of the object
There are two possible situations:
- When m is positive, y' has same sign as y: this means that the image image is upright
- When m is negative, y' has opposite sign to y: this means that the image is upside down
Therefore, the correct option representing an upright image is
B. +m
Answer:
15.8 V
Explanation:
The relationship between capacitance and potential difference across a capacitor is:
where
q is the charge stored on the capacitor
C is the capacitance
V is the potential difference
Here we call C and V the initial capacitance and potential difference across the capacitor, so that the initial charge stored is q.
Later, a dielectric material is inserted between the two plates, so the capacitance changes according to
where k is the dielectric constant of the material. As a result, the potential difference will change (V'). Since the charge stored by the capacitor remains constant,
So we can combine the two equations:
and since we have
V = 71.0 V
k = 4.50
We find the new potential difference: