As a reverse DC voltage is applied across the diode, its capacitance varies. The higher the voltage, the less the capacitance. This is due to depletion layers of the diode junction, but we wont get into details here. This variable capacitor in conjunction with the stub, which is actually an inductor (coil) is the basis of our voltage controlled oscillator! As the voltage increases across D5, the frequency of oscillation increases.
Current as a function of time: Based upon the given information, we will be determining the Amplitude (A), period (and thus, B), and the phase shift (C). Given information states there is not a phase shift, therefore the value of D is zero and does not need to be recorded throughout the problem. The Amplitude (A) or maximum for the current has been given: 5 Amps. This indicates that the range will span from -5 to 5 on the y-axis. It is also given that at t=zero (time=zero) the current is equal to 5 Amps, meaning there is a negative phase shift (or phase shift to the left).
Figure 2 shows a circuit with a resistor R = 1.0 × 103 Ω, and a battery with potential difference of VB = 5.0V . (a) Solve the circuit in Figure 2. That is, find all unknown currents, voltages, and resistances. (b) What is the direction of the current? Note: I want the direction of the conventional current.
Limits to computing power are caused by throughput bottlenecks between the CPU and__________. a. input devices b. output devices c. memory d. other CPUs 5. Which device uses a lot of power and gives off a lot of heat? a. Integrated circuit b. Transistor c. MOSFET d. Vacuum tube 6.
If there are higher levels of potassium, then the resting membrane potential will be less than normal and an action potential will be not likely with the same amount stimulation. More voltage is needed. • Explain how hypokalemia will initially affect the resting membrane potential and the generation of an action potential. The resting membrane potential is based on the polarization of the cell. If there are lower levels of potassium, then the resting membrane potential will be higher than normal and an action potential will be more likely with less stimulation.
Purpose: The following lab was conducted in order to determine the iron (〖Fe〗^(2+)) content in an unknown sample by way of reduction-oxidation titration using a standardized potassium permanganate solution. Theory: Titration is one of the most commonly used methods for determining the amount or concentration of an unknown substance. Chemical analysis can be performed on redox titrations, if the following conditions are met: “The reaction is thermodynamically spontaneous enough to be stoichiometric”, “The reaction is kinetically fast enough to give operationally ‘instant’ results”, “No side reactions occur”, and “a satisfactory indicator exists”. These conditions are what makes potassium permanganate (〖KMnO〗_4) a very useful analytical oxidation agent as it easily fits the criteria. The half reactions for this system are: Oxidation of 〖Fe〗^(2+): 〖Fe〗^(2+)→ 〖Fe〗^(3+)+1e^- Reduction of 〖MnO〗_4^-: 〖MnO〗_4^-+8H_3 O^++5e^-→ 〖Mn〗^(2+)+12H_2 O Which produces the following overall equation: 〖MnO〗_4^-+8H_3 O^++5〖Fe〗^(2+)→5〖Fe〗^(3+)+〖Mn〗^(2+)+12H_2 O Equilibrium is initially obtained at a very slow rate, therefore the titration is carried out in the presence of excess sulphuric acid (H_2 〖SO〗_4) at a high temperature; in order to drastically increase the rate at which equilibrium is attained.
Exercise 4.1.2: The voltage for registering a bit of 1 on Ethernet can be as low as 2.5 volts or even 1 volt. Why is this so low when the capacity for transmitting electricity on the copper wire is so high? Use your textbook and Internet research to support your answer. Because the voltage used to transmit data needs only be high enough for the receiver to detect it. Making the voltage higher would make the receiver electronics more difficult.
The string is tied onto a thin metal bar at A and fixed at B. A vibration generator causes the bar to oscillate at a chosen frequency. Explain how a stationary wave is formed. Then describe the key features of the stationary wave shown in Figure 4. * Waves reflect off the clamp and the rod * Waves travelling in opposite directions superpose * Waves have same wavelength and frequency, similar amplitude * Always cancellation at nodes and constructive superposition at antinodes * Energy is not transferred along string * 4 nodes where there is zero amplitude * 3 antinodes where amplitude is maximum * Wavelength 0.80m * End antinodes in phase and middle and ends in antiphase * Between node and antinode, amplitude of oscillation increases On her next jump the gymnast decides to reach a height above position B.
B, C and D Electrical Circuit – an electrical device that provides a path for electrical current to flow Frequency – The cycles per second of alternating current, measured in Hertz Amplitude – the maximum difference of an alternating electric current or potential from the average value Phrase – is a position of a point in time on a waveform cycle Bit time – the time it takes for one bit to be ejected from a network interface card at a standard speed Encoding Scheme – a system used by computers to represent data as characters Unshielded twisted-pair – The word unshielded refers to the fact that UTP cables have no added shielding materials to prevent EMI problems Core- The light source on one end of the cable shines light into the core Cladding- surrounds the core, for the entire length of the cable, and reflects the light into the core Radio waves- work well for networking because as a waveform, radio waves can be changed (modulated) over time to send data. Wireless WAN- used often in mobile phone network/mobile network Wireless LAN- don’t not use cables and do use radio waves to send data Access Point – all user devices communicate only through the AP, most WLAN’s use this wireless
Another stimulus during the refractory period generally does not cause a new action potential. Once the axon has repolarized to - or near to - the resting membrane potential, a new action potential can be generated. During an action potential, depolarization of a section of the plasma membrane causes the adjacent section of the axon to also depolarize above threshold and generate a new action potential. In this way, the action potential is propagated down the axon. The amplitude (height of voltage spike) during depolarization remains constant as the action potential travels down the length of the axon.