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Why is a bulb most likely to fail when the current is first switched on?
Wiki User
∙ 11y ago
Light bulb filaments glow rather than burn because of the lack of oxygen within the vacuum of the bulb. Over time, the heating and contracting of the filament and the glass surrounding it creates a leak in the base of the bulb causing the vacuum to be lost and allowing oxygen to enter the bulb. It is during the contracting phase, which happens as the bulb cools after being turned off, that eventually the seal is lost. When this happens, oxygen is allowed to enter and the next time the bulb is turned on, the filament, now exposed to the oxygen, burns out.
Wiki User
∙ 18y ago
Wiki User
∙ 11y agoWhen globes are first turned, they are cold and the filament is at it's lowest resistance. Therefore the current flow is at it's highest and the power absorbed by the globe caused it to go well above its normal range. This leads it be be it's most susceptible immediately on turn on. It is survives this, then the high temperature of the filament causes a corresponding high filament resistance and hence a lower current.
The flow of current is lowest through a high resistance and highest through a low resistance (assuming the voltage is constant).
The filament's electrical resistance increases very dramatically as the temperature increases from cold (or ambient) to working temperature.
Wiki User
∙ 11y agoAn underwater pool light is designed such that the low voltage electrical contact is water tight. Water is a conductor so if it is wet between contacts this could cause the bulb to burn out. Another thing to check is the bulb casing. If there is any water inside the bulb then this could also have caused a short. Finally, it could in fact be a faulty bulb with a bad filament. At any rate unless you did something wrong try for a refund from the supplier.
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What uses more electricity a lit light bulb or an empty socket of the same rating switched on?
When the bulb is lit it uses energy. When there is no bulb, no energy is used even if it is switched on.
What is electronic blast for a CFL lamp?
The electronic BALLAST is a circuit that limits the current through the fluorescent bulb to the design value. It also provides a pulse of high voltage to start the bulb conducting when it is switched on.
Will the bulb light if the filament is broken Why?
No, the broken filament breaks the connection which electricity needs to complete the circuit.
You see light as soon as a light bulb is switched on?
yes
Does a burned out bulb use electricity?
Assuming it's a filament (incandescent) bulb, no. When a bulb burns out, the tiny wire in the bulb is broken, and the electricity can no longer pass through the bulb. It's the same as if it was switched off.
What happens when the torch is switched on?
current flows and we have light from bulb....
Why do light filament bulbs usually blow when they are first switched on?
because when they are first switched on a large surge of electrical current flow through a cold filament. When you first switch on the bulb the resistance is small, so you get a current surge which breaks the weakened filament. The filament is weakened by repeated heating and cooling from the bulb being turned on and off; which makes it brittle.
What happens when a bulb is switched on?
when a light bulb is switched on it will blown..............
What uses more electricity a lit light bulb or an empty socket of the same rating switched on?
When the bulb is lit it uses energy. When there is no bulb, no energy is used even if it is switched on.
What is electronic blast for a CFL lamp?
The electronic BALLAST is a circuit that limits the current through the fluorescent bulb to the design value. It also provides a pulse of high voltage to start the bulb conducting when it is switched on.
Will the bulb light if the filament is broken Why?
No, the broken filament breaks the connection which electricity needs to complete the circuit.
You see light as soon as a light bulb is switched on?
yes
Meaning of 60watt's in 60watt's bulb?
60 Watts is the amount of electrical power the bulb uses when it is switched on.
Does an energy saver coiled bulb continue to flicker when switched off?
no
How do you know when electric current is flowing in a light bulb circuit?
You know if current is flowing in a bulb circuit because, if there is enough power (voltage times current), the bulb will illuminate. If there is current, but not enough power to illuminate the bulb, you will need to measure the current with an ammeter to see if there is any current.
Watt is the current allowed to flow through a bulb?
The current flowing through a bulb is equal to the (voltage across the bulb) divided by the (bulb resistance), and can be expressed in Amperes. The rate at which the bulb dissipates energy is equal to (voltage across the bulb) times (current through the bulb), and can be expressed in watts.
What is the energy called in a light bulb which is switched off?
Potential energy, maybe?
