Answer:
<em>The primary coil has 13,400 turns</em>
Explanation:
<u>Voltage Transformers</u>
A transformer is an electrical apparatus that converts an alternating electrical voltage to another. Step-down transformers lower the voltage from higher levels (kilovolts) to consumer levels (120/240 Volts).
The ratio between both voltages can be computed as

Where V1 is the primary voltage and V2 is the secondary voltage. This ratio depends on the turns ratio of the coils wounded in a common magnetic core.

Being N1 the number of turns of the coils of the primary side and N2 the number of turns in the secondary coil. Both relations give us

Solving for N1

We have:

Calculate N1

The primary coil has 13,400 turns
Speed = distance / time = 55 / 0.75 = 73.3 miles per hour.
Answer:
Q = 4 Q₀
Explanation:
This is an exercise on capacitors, where the capacitance is
C = 
if we apply the given conditions
C = \epsilon_{o} \ \frac{2A}{0.5d}
C = 4 \epsilon_{o} \ \frac{A}{d}
let's call the capacitance Co with the initial values
C₀ = \epsilon_{o} \ \frac{A}{d}
C = 4 C₀
The charge on each plate of a capacitor is
Q = C ΔV
If the potential difference is maintained, the new charge is
Q = 4 C₀ ΔV
let's call
Q₀ = C₀ ΔV
we substitute
Q = 4 Q₀
Solar cells are made out of silicon wafers. These are made out of the element silicon, a hard and brittle crystalline solid that is the second most abundant element in the Earth's crust after oxygen. If you're at the beach and see shiny black specks in the sand, that's silicon.
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