The density increases.
When gases are compressed, their volume decreases, and the resulting pressure increases. The temperature will change if either P or V are held constant. Since the volume decreases, then density, or m/V, increases.
P×V ~ T
Answer:
Xc= 17.267 Ω, Z= 415.5 Ω, I= 0.537 A
Explanation:
Em = 223 V
f= 300 Hz, R = 222 Ω, L = 147 mH, C = 23.1 μF
a)
Capacitive reactance = Xc=?
Xc= 
Xc=1/2pi *399*23.1*10^-6
Xc= 17.267 Ω
b).
Z=
Xl= 2π * f * L
Xl= 2π * 399 * 147 * 
Xl= 368.5 Ω
Z=
= 
Z= 415.5 Ω
c).
Current:
I= V / Z= Em / Z
I= 223/415.5
I= 0.537 A
In some unusual applications of unusual components, I can think of unusual electric circuits where a switch may be connected in parallel with a device in order to control it.
But I'm sure this is not what's intended in a question on the high-school level.
Until you get in a situation with tricky applications in a tricky circuit, your switches will always be connect <em>in series</em> with the devices they control.