Question 2.
A transmission system at a radio station consists of essentially the following devices:
1. An oscillator, which converts a direct current into a high-frequency alternating current.
2. A transmitting antenna, which sends out radio waves having the same frequency as the current supplied by the oscillator.
3. A microphone, which picks up the sound waves and converts them into a suitable electric current with the same pattern as the sound waves.
4. A modulator, which enables the waves produced by the antenna to “carry” the pattern of the sound waves picked up by the microphone.
<span>The answer is C. Oscillator</span>
Answer:
The correct answer is (a), heating and soaking at a temperature above the austenitizing level followed by rapid cooling.
Explanation:
Tempering is a heat treatment that is performed to change microstructure of steel <em>and increase it's hardness.</em>
It is done by heating above the austenitizing level, because for this heat treatment it's necesary to heat the steel to get <em>austenite structure</em> that is the <em>alotropic form of gamma iron.</em>
The procedure of tempering, continues with rapid cooling, because this way you get the microstructure with the best hardness properties, that is <em>martensite.</em>
Answer:
-9.8 m/s²
0 m/s
Explanation:
Average acceleration is the change in velocity over change in time.
a = Δv / Δt
a = (-9.8 m/s − 9.8 m/s) / 2.0 s
a = -9.8 m/s²
Average velocity is the change in position over change in time.
v = Δx / Δt
v = (0 m − 0 m) / 2.0 s
v = 0 m/s
impossible because fractional charges do not exust
