The core of a transformer should be laminated to minimize energy loss due to the production of an eddy current.
We know, tungsten wire has low resistance and it cannot convert electrical energy to heat energy and also oxidize at high temperature. So, it is not used in the heater.
We know, nichrome is an alloy of nickel and chromium metals. It has high resistance and doesn't oxidize at very high temperatures. So, nichrome wire is used in an electric heater but not a copper wire.
A thin and long tungsten wire is used in an electric bulb because it has very high resistivity and has a very high melting point. So, it doesn't melt even if the light bulb has a high temperature.
We know, inert gas doesn't take part in any reaction due to its stable state of electronic configuration. As a result, using its property, to avoid chemical reaction inside bulb even in extreme temperature inert gas is used to fill the electric bulb.
We know that the birds don't touch the earth's surface while sitting on power lines. So, the current that flows to their body and flows back again to the wire. Therefore, the bird doesn't get any shock. Hence, birds are found sitting on high voltage transmission lines.
We know that neutral wire (earthing wire) carries the leaked current to the earth. If we touch the earthing wire also, the current flows to our body and returns to the wire, and goes to the ground to be neutralized. So, we don't feel shocked even if we touch a neutral wire.
We know, filament lamp converts only 10% of electrical energy to light energy but a fluorescent lamp converts 30% of electrical energy into light energy. So, a fluorescent lamp of 40W is better than a filament lamp of 40 W.
DC is not used in a transformer because it cannot change the electromotive force of DC because the magnitude of the DC doesn't change. So, AC is used as its magnitude and polarity change.
We know, electric current flows from phone wire to the power load. So, to disconnect or block the current right at phase wire during the case of overload, a fuse is connected to a phase wire.
We know, electric current flows from the phase wire to the power load. So, to block the current right at phase wire switches connected to a phase wire.
a. Live wire and neutral wire.
b. AC and DC.
c. Filament and...
An inverter is an electric device that changes AC into DC and vice versa. It is used to convert AC source to DC source or DC source to AC source.
A battery charger is a device that is used to put energy into a secondary cell or rechargeable cell by forcing an electric current through it.
It is used to charge the battery of the mobile phone, automobile, laptop, etc.
A transformer that converts high voltage AC to low voltage AC is called step-down transformers.It is used at the power sub-station to decrease the AC voltage before distribution.
A transformer is a device that converts high voltage AC to low voltage AC of the same frequency and vice versa The function of the step-up transformer is that it converts the low voltage of current to high voltage.
A current-carrying wire exerts a force on a magnetic compass and defects it from its usual north-south position which is called the motor effect.
When current is passed through a conductor, a magnetic field is developed around it.
An electromagnet is made by using a cylindrical form of an insulated copper coil having a large number of close turn is a solenoid.
It is used to strengthen the magnetic field. The device that breaks the circuit is MCB.
fig. Electric bell
When a current is passed through a wire, it produces a magnetic field around it which is called the magnetic effect of an electric current.
When the current is passed through the wire of high resistance, it becomes extremely hot and produces heat which is called the heating effect of an electric current.
When the current is passed through a wire of high resistance which becomes extremely hot and produces light which is called the lighting effects of an electric current.
The device which converts mechanical energy into electrical energy is called a dynamo.
The process of producing current in a closed coil due to the relative motion between magnet and coil is called electromagnetic induction.
The rate at which electrical work is done or the rate at which electrical energy is consumed called electric power consumption.
1 KWhr can be defined as the amount of electrical energy consumed by an electrical appliance having a power ratio of 1KW for 1 hrs.
The current which changes its magnitude and polarity is called AC.
The current that has fixed magnitude and polarity is called DC.
The frequency of current distributed in Nepal is 50 Hz means the polarity of the current changes 50 times in a second.
The wire which produces heat by passing a current through it is called the heating element.
Any 5 points to be remembered during household wiring are:
The flow of electrons in a definite direction is called current electricity.
i. Open electric circuit:An electric circuit in which no current is flowing is called an open circuit.
ii. Closed electric circuit:An electro circuit in which electric current is flowing continuously is called a closed electric circuit.
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