Advertisements
Advertisements
Question
Give a scientific reason:
For electric power transmission, copper or aluminium wire is used.
Advertisements
Solution
- Copper and aluminium are excellent electrical conductors.
- Since the resistance of copper and aluminium is very low, the amount of heat generated while carrying an electric current through them is also low.
Therefore, copper or aluminium wires are used for electricity transfer.
APPEARS IN
RELATED QUESTIONS
Why does the cord of an electric heater not glow while the heating element does?
How does the resistance of a wire vary with its area of cross-section?
When current is switched ‘on’ in a room heater, it ______.
What is nichrome? State its one use.
The elements of electrical heating devices are usually made of:
(a) tungsten
(b) bronze
(c) nichrome
(d) argon
Give a scientific reason.
Tungsten metal is used to make a solenoid type coil in an electric bulb.
Statement 1 : Electric current ( flow of electrons ) creates heat in the resistor.
Statement 2 : Heat in the resistor is created according to the rule of energy conservation.
Explain Statement 1 with the help of Statement 2.
Why does tungsten metal used to make solenoid type coil in an electric bulb?
Compute the heat generated while transferring 96000 coulombs of charge in two hours through a potential difference of 40 V.
The ‘live’ and the ‘neutral’ wires have potential difference of _______.
These days when current in the circuit suddenly increases _______ switches are used.
Which of the following substance contracts on heating?
What is the heating effect of electric current?
What is a short circuit?
What is used to turn off the sudden increase in current in the electrical circuit of the house nowadays?
True or False – If False give the correct answer
The fuse wire does not melts whenever there is overload in the wiring.
Explain the heating effect of electric current.
Heating effect of current is called ______
Which of the following is correct?
An electric iron consumes energy at the rate of 420 W when heating is at the maximum rate and 180 W when heating is at the minimum rate. The applied voltage is 220 V. What is the current in each case?
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?
How does use of a fuse wire protect electrical appliances?
Can we use the same fuse in a geyser and a television set? Explain.
Explain the working of an electric fuse.
______ wire is used in the filament of the bulbs.
An electric fuse is a wire made up of a material having ______ melting point.
A trip switch is a ______ safety device.
The electric fuse works on the Joule heating principle.
Explain why fuse wire is always connected in a series arrangement.
Tara, after completing her exams, went to her grandmother's house along with her younger brother Rahul. One day, Rahul came home after playing and switched on the fan and air conditioner. At the same time, his grandmother was preparing a milkshake for him using a mixer. Suddenly, they heard a big sound and the electricity of the house got shut down. Tara is called an electrician. He said the main reason for supply to shut down was overloading.
- What is overloading?
- Is overloading and short the same? When does short-circuiting take place?
- How can the effects of overloading be avoided?
What is the heating effect of electric current?
Write an expression for the amount of heat produced in a resistor when an electric current is passed through it stating the meanings of the symbols used.
State the law that explains the heating effect of current with respect to the measurable properties in an electrical 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.
