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So, the new resistance, after doubling the length of the wire, becomes twice of the original resistance. Hence, if the length of a wire is doubled, then its resistance becomes doubled. Note: We must not get confused as to why the area of the cross section of the wire is taken to be constant.
V=IR; current is doubled when voltage is doubled. Doubling resistance for a constant battery voltage will cause the current to be halved.
Answer. . Decrease its current and decrease its voltage.
The main function of resistors in a circuit is to control the flow of current to other components. Take an LED (light) for example. If too much current flows through an LED it is destroyed. So a resistor is used to limit the current.
What is the power () of an electric circuit with a current () of 6.5 A and a voltage (V) of 120 V? The formula for power is P= IV. A. 27.
A resistor has the ability to reduce voltage and current when used in a circuit. The main function of a resistor is to limit current flow. Ohm’s law tells us that an increase in a resistors value will see a decrease in current. To reduce voltage, resistors are set up in a configuration known as ‘voltage divider’.
To reduce voltage in half, we simply form a voltage divider circuit between 2 resistors of equal value (for example, 2 10KΩ) resistors. To divide voltage in half, all you must do is place any 2 resistors of equal value in series and then place a jumper wire in between the resistors.
A voltage spike is a sudden increase in voltage that lasts for less than 3 nanoseconds. Voltage spikes and surges can be caused by lightning, static electricity, magnetic fields, and internal changes in voltage use. The best way to protect your electronic equipment is with the use of a surge protector.
How Do I Prevent Power Surges?
A surge protector (or spike suppressor, or surge suppressor, surge diverter, SPD or TVSS) is an appliance or device intended to protect electrical devices from voltage spikes in alternating current (AC) circuits.
It can discharge the back-current from lightning spreading from the earth conductor to the network conductors. Type 1 SPD is characterized by a 10/350 µs current wave. The Type 2 SPD is the main protection system for all low voltage electrical installations. Type 2 SPD is characterized by an 8/20 µs current wave.
What are the Signs of a Power Surge?
To calculate the surge current, divide the voltage waveform by the impedance of the connection between the originating event and the system. You can determine the impedance by looking at the electrical connection between the origination of the surge and the protected line.
Definition: Voltage surge is defined as the sudden rise in excessive voltage which damages the electrical equipment of an installation. The overvoltage in the lines occurs because of a rise in voltage between both phases and between phase and ground.
When a synchronous motor is used for driving a varying load, then a condition known as hunting is produced. These dampers consist of short- circuited Cu bars embedded in the faces of the field poles of the motor (Fig. 38.57).
Lightning With your electrical system designed to channel electricity, a lightning strike can easily compromise it. When lightning does strike your electrical system, it has no choice but to accept the overwhelmingly excessive current. This creates a massive spike, therefore creating a power surge.
On increasing the shaft load gradually load angle will increase. As a result of rotor acceleration above synchronous speed the load angle decreases. So once again no equilibrium is attained. Thus rotor swings or oscillates about new equilibrium position. This phenomenon is known as hunting or phase swinging.
Elsewhere in the world arguably the most common external cause of voltage surges come from lightning. While lightning may actually strike the circuit itself causing a power surge, a far more common cause of voltage surges is lightning hitting circuits nearby.