Answer:
k = 2.279
Explanation:
Given:
Magnitude of charge on each plate, Q = 172 μC
Now,
the capacitance, C of a capacitor is given as:
C = Q/V
where,
V is the potential difference
Thus, the capacitance due to the charge of 172 μC will be
C = [tex]\frac{(172\ \mu C)}{V}[/tex]
Now, when the when the additional charge is accumulated
the capacitance (C') will be
C' = [tex]\frac{(172+220)\ \mu C)}{V}[/tex]
or
C' = [tex]\frac{(392)\ \mu C)}{V}[/tex]
now the dielectric constant (k) is given as:
[tex]k=\frac{C'}{C}[/tex]
substituting the values, we get
[tex]k=\frac{\frac{(392\ \mu C)}{V}}{\frac{(172)\ \mu C)}{V}}[/tex]
or
k = 2.279