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If the graph is for Ohmic components e.g resistor or wires
-Constant gradient
-V is proportional to I
The second graph is for Non-Ohmic components
e.g Filament lamps/diodes
-(v is NOT proportional to I)
-Gradient is high at the origin (0,0) and low at the top due to an increase in resistance
Hope this helps!!
I couldn't put the pictures on, but just Google a Filament lamp graph and they will come up :)
What else can I help you with?
Are voltamps equal to watts?
Yes, in direct current (DC) circuits where the voltage and current are in phase, voltamps (VA) are equal to watts (W). However, in alternating current (AC) circuits where the voltage and current may not be in phase, the relationship between voltamps and watts can vary depending on the power factor of the load.
Why are the readings on a ammeter always different?
The readings on an ammeter indicate the current being drawn by a load in a circuit. This load is basically a resistance to current flow. The higher the resistance, the lower the current. The supply voltage has a direct effect on current flow. The higher the voltage applied, the higher the current will be. So the readings will vary on the ammeter according to fluctuations in load and or resistance of the circuit and the applied voltage.
How many watts does a slushy machine use?
It depends. Check the back of the machine. There will be a sticker that says the voltage and current rating. It may already say the wattage, but if it doesn't, multiply the voltage by the current. Remember milliamps are .001 A. So if the voltage rating on the slushy machine is (I doubt the current is this low) 120 and the current is 500mA, then the wattage is 60W. Its likely that the voltage rating be something like 125 and the current 4A, but I've never used one, so just use the P=VI formula.
What is the power factor of a DC system?
It would be unity, or 1.0. Since the voltage in a DC circuit does not vary with time, there can be no phase displacement of the current waveform, and therefore the current could not lead or lag the voltage waveform.
What is diffence between ac volt?
AC is short for alternating current and DC is short for direct current. In the case of an AC signal the current is going backward and forwards at the rated frequency of the signal (so 240V at 50Hz would mean the terminals vary between 240V and -240V and back again 50 times a second). If you were electrocuted by AC you would be repelled away from it. In the case of a DC signal the current is in one direction and the voltage will remain either positive or negative (so a 240V signal would stay at 240V and the current would flow positive to negative - conventional current). If you were electrocuted by DC you would stick to it and probably suffer some serious burns, which is one reason for high voltage electrical supplys being AC. I hope that answers your question!
When voltage is reduced 75 percent current is reduced?
This statement is correct.
How does current vary with the resistance in the circuit if the voltage is constant?
Inversely. As resistance increases, current dereases; given that the applied voltage is constant.
What is meant by a nominal current?
The word nominal means the lowest possible safe amount. So, nominal current or nominal voltage is the lowest amount necessary to perform an electrical function like keeping a light turned on.AnswerThe original answer is incorrect. 'Nominal' simply means 'named'. So a 'nominal voltage' is the 'named voltage', as opposed to an 'actual voltage'. For example, the nominal voltage of residential supplies in the UK is 230 V; however, this value is allowed to vary between +10/-6% of the nominal voltage. In other words, a nominal voltage of 230 V may vary between 216 V and 253 V.
Are voltamps equal to watts?
Yes, in direct current (DC) circuits where the voltage and current are in phase, voltamps (VA) are equal to watts (W). However, in alternating current (AC) circuits where the voltage and current may not be in phase, the relationship between voltamps and watts can vary depending on the power factor of the load.
Does the voltage that runs through different appliances vary according to the resistance of the appliances?
No, it is the current (amperes) that vary according to the resistance.
Why induction type instrument canot be used for dc measurements?
Induction is a property of voltage changes, which does not occur with Direct Current devices. There are exceptions, such as the coil of an automobile, which charges up to a high voltage between ignition discharges, but the voltage supplying the coil does not vary.
What happens to the current when the voltage becomes limited at the knee?
A: Perfect example is a zener. As input voltage increases the current at the knee increases almost linearly at the zener voltage. If the inputs varies up or down then the current will vary up or down at the preset voltage making a zener a voltage regulator because of this feature
How does load current vary with the load resistance?
Their relationship is only dependent on the voltage lost across that resistor; voltage equals resistance times current, so increasing the current for a given voltage will require a decrease in the resistance, and vice versa.
What is the role of voltmeter?
vary the rheostat by step by step note out the two voltmeter readings
How can you select the current values for welding?
The amount of current (amps) is controlled by the user. It's done with a variable resistor. Another thing to note is whether you are welding constant current or constant voltage. If you are welding constant current, the voltage will vary and a set Amp measure will remain constant. With constant voltage, the current will vary and that's determined by the resistance. Constant voltage should be an easier set up. I'm not 100% sure but most stick welding is constant current, which is why increasing the arc length produces more heat, because more arc length should increase the resistance, which would cause the welding machine to increase voltage to keep the current constant.
Why are the readings on a ammeter always different?
The readings on an ammeter indicate the current being drawn by a load in a circuit. This load is basically a resistance to current flow. The higher the resistance, the lower the current. The supply voltage has a direct effect on current flow. The higher the voltage applied, the higher the current will be. So the readings will vary on the ammeter according to fluctuations in load and or resistance of the circuit and the applied voltage.
Why is the voltage level not constant in electrical power transmission?
Changes in load causes the load current to change, resulting in changes in voltage drop along conductors. This means that the 'receiving end' voltage will vary.
