0
Volts = Current x Resistance. The voltage is where the potential resides for the amount of current flowing through a resistance. Think about the voltage as a potential source of electrons that then flow through a circuit depending on the Load, or resistance in this example.
Wiki User
∙ 14y ago
Add your answer:
Earn +20 pts
Is it true that for the same resistance the greater the voltage the greater the current?
true
Is Ohm's law states that voltage in a circuit is equal to resistance times current true or false?
True. Ohm's law states the voltage is resistance times current.
In RC circuits the voltage leads the current?
Inductive. Used to remember this by "Eli" the "ice" man. "(e) Voltage (l) (Inductive circuit) (i) current", the ,"(i) Current (c) (capacitive circuit) (e) voltage, man.
How can current lag or lead voltage in an AC circuit isn't current a function of voltage etc?
Current can lag or lead voltage in an AC circuit when the load is what we call reactive. The idea that current is purely a function of voltage only applies when working with DC, or when working with purely resistive loads, such as light bulbs and toasters. Not so, when dealing with motors and power supplies. What happens is that an inductor resists a change in current. That means that, given a particular voltage and current at a particular instant of time, if you change the voltage, the current will not immediately follow - it will lag - because the inductor is a stored energy device. Similarly, a capacitor resists a change in voltage, which means that if you change the current, the voltage will not immediately follow - it will lag - also because the capacitor is a stored energy device. Flip over current and voltage in the analysis of a capacitor, and you find that the current will lead the voltage, as opposed to the inductor's current lagging the voltage. This causes the phenomenon of power factor, which is basically the cosine of the phase angle between voltage and current. Power factor is the ratio of apparent power to true power.
When electric current is following in a curcuit if the voltage applied to the curcuit is increased the resistance will decrease true or false?
true
Is it true that electrical current flows from a state of rest to a high pressure state?
No, it is not true. An electrical current (which is a flow of electrons) can only flow from a higher pressure state (higher voltage) to a lower pressure state (lower voltage).
When you stepup ac voltage the current drops.What will happen with CURRENT if DC is stepped up?
WHEN YOU STEP UP THE VOLTAGE AND THE LOAD IS THE SAME MORE CURRENT WILL FLOW NOT LESS. AND THAT WILL HOLD TRUE FOR DC AS WELL. IF THE LOAD REMAINS THE SAME AND YOU INCREASE THE CURRENT AC OR DC THE VOLTAGE WILL INCREASE
What happens to the applied voltage when a change in circuit resistance occurs?
When a dc supply is connected to a resistor, current flows. The current in amps is equal to the supply voltage divided by the resistance in ohms. The power used is the voltage times the current, and that appears as heat in the resistor, which might become hot to touch.
If it is the current that causes the damage why do dangerous places have signs warning you of the high voltage?
True, current causes the damage. But current cannot flow unless there is voltage present to push it. Imagine a live, exposed wire sticking out of a wall. It has voltage, but that's all. No current flows until the circuit is completed by something. That something can be you! At the instant you touch the wire, current flows from the wire, through you, and into the ground. If the current is high enough, it can injure or even kill you. The higher the voltage, the more current will flow once you touch the wire. A sign warning of high current would be inaccurate, because before you touch the wire, the current is zero. And low voltages cause very little current to flow through a human body under normal conditions. So, high voltage does indeed pose a potential threat, and thus warrants a warning. It's like the flammable warning on a can of gasoline. Right now, it just sits there. It is not hot, there is no flame. Yet. But we both would agree it has the potential to burn us to a crisp under the right conditions. Gasoline is not what hurts you. The flame it produces is what does the damage, yet we still put the warning on the gasoline. Voltage is like that. It's the current (flame) that does the damage, but it comes from the voltage (gasoline), so that's what we warn of.
They say current is what kills people and not voltage but why then in electronics does high voltage burn your components but high current does not?
This is a 'chicken and egg' situation. The current passing through your body is determined by the voltage applied across your body, together with the resistance of the current path. So whilst it is true that it is the current that harms you, the voltage has to be high enough to cause the necessary amount of current to flow. In other words, it is equally valid to say that it is the voltage level that causes electrocution. An analogy might be, which kills you: the height through which you fall, or hitting the ground? Obviously, hitting the ground is what kills you, but the height from which you fall determines how hard you are going to hit the ground. As far as damage to electrical circuits is concerned, excessive voltage is responsible for insulation breakdown, while current is responsible for components to overheat. So high current will most certainly damage those components.
Describe the relationship between voltage and current for the resistors?
R = V/I Therfore the resistance is proportional to the voltage and inversely proportional to the current.
For a formula of resistance. Is it correct to divide the current by the voltage rather than the other way around?
Ohm's law says V=IR, where V is voltage, I is current and R is resistance. To get resistance, divide both sides by I: V/I = R. If you check the units, you'll see that they work out this way, but would not work out correctly if you tried I/V. (but remember, this only applies to systems which obey ohm's law, which is usually not quite true in real systems, but is generally true in textbook problems)
