Advertisements
Advertisements
प्रश्न
Explain the application of heating effect of electric current in an electric bulb with a diagram.
Advertisements
उत्तर
- Electric bulb works on the principle of heating effect electric of current.
- The solenoid type coil of bulb has high resistivity and very high melting point.
- When current is passed through the bulb, solenoid type coil of bulb gets heated to high temperature (upto 3400 °C) and starts glowing.
संबंधित प्रश्न
Why are the conductors of electric heating devices, such as bread-toasters and electric irons, made of an alloy rather than a pure metal?
How does the resistance of a wire vary with its area of cross-section?
When current is switched ‘on’ in a room heater, it ______.
Derive the expression for the heat produced due to a current 'I' flowing for a time interval 't' through a resistor 'R' having a potential difference 'V' across its ends. With which name is this relation known?
The current passing through a room heater has been halved. What will happen to the heat produced by it?
The current passing through an electric kettle has been doubled. The heat produced will become:
(a) half
(b) double
(c) four time
(d) one-fourth
How does the wire in the filament of a light bulb behave differently to the other wires in the circuit when the current flows?
What property of the filament wire accounts for this difference?
Give Scientific reasons.
In the electric equipment producing heat e.g. iron, electric heater, boiler, toaster etc, an alloy such as Nichrome is used, not pure metals.
Give a scientific reason:
For electric power transmission, copper or aluminium wire is used.
Give Scientific reason.
In practice, the unit kWh is used for the measurement of electrical energy, rather than joule.
Heat energy is being produced in a resistance in a circuit at the rate of 100 W. The current of 3 A is flowing in the circuit. What must be the value of the resistance?
An electric iron of 1100 W is operated for 2 hrs daily. What will be the electrical consumption expenses for that in the month of April? (The electric company charges Rs 5 per unit of energy).
Why does tungsten metal used to make solenoid type coil in an electric bulb?
Name any six domestic appliances based on the heating effect of electric current.
Answer the following question:
what is the heating effect of the electric current? state any four applications of it?
Write the mathematical expression for Joule’s law of heating.
Compute the heat generated while transferring 96000 coulombs of charge in two hours through a potential difference of 40 V.
In an electric bulb, coil of _______ metal is used.
These days when current in the circuit suddenly increases _______ switches are used.
A coil of an alloy _______ is used in electric heater cooker as a resistor.
Which of the following substance contracts on heating?
Explain the heating effect of electric current.
Name any two appliances which work under the principle of heating effect of current.
Which of the following is correct?
A current of 1 A is drawn by a filament of an electric bulb. Number of electrons passing through a cross-section of the filament in 16 seconds would be roughly:
An electric kettle consumes 1 kW of electric power when operated at 220 V. A fuse wire of what rating must be used for it?
What is Joule’s heating effect? How can it be demonstrated experimentally? List its four applications in daily life.
When a switch is in OFF position,
- circuit starting from the positive terminal of the cell stops at the switch.
- circuit is open.
- no current flows through it.
- current flows after some time.
Choose the combination of correct answer from the following.
Your teacher has shown you the following activity.
Activity: Teacher has wound a long insulated piece of wire around an iron nail in the form of a coil. Free ends of the wire are connected to a cell through a switch as shown in the following figure. The current is switched on and some pins are placed near the ends of the nail.
Write down any three questions that come to your mind about this activity.
Assertion: A current-carrying wire should be charged.
Reason: The current in a wire is due to the flow of free electrons in a definite direction.
Name the effect of the current responsible for the glow of the bulb in an electrical circuit.
An electric fuse is a wire made up of a material having ______ melting point.
An electrochemical cell converts ______ energy into ______ energy.
A trip switch is a ______ safety device.
Define the following:
Electrolyte
Anannya responded to the question: Why do electrical appliances with metallic bodies are connected to the mains through a three-pin plug, whereas an electric bulb can be connected with a two-pin plug?
She wrote: Three-pin connections reduce heating of connecting wires.
- Is her answer correct or incorrect? Justify.
- What is the function of a fuse in a domestic circuit?
An electric iron is rated 220 V, 2 kW. If the iron is used for 3h daily find the cost of running it for one week if it costs ₹ 4.25 per kWh.
