Advertisements
Advertisements
Question
What is the energy conversion when an electric current passes through a metallic wire?
Advertisements
Solution
When an electric current passes through a metallic wire, the wire becomes hot and the whole of electric energy is converted into heat energy.
RELATED QUESTIONS
How much energy does a 100 W electric bulb transfer in 1 minute?
(a) 100 J
(b) 600 J
(c) 3600 J
(d) 6000 J
A bulb of 40 W is used for 12.5 h each day for 30 days. Calculate the electrical energy consumed.
The diagram below shows a magnetic kept just below the conductor AB which is kept in North South direction.
(i) In which direction will the needle deflect when the key is closed ?
(ii) Why is the deflection produced ?
(iii) What will be the change in the deflection if the magnetic needle is taken just above the conductor AB ?
(iv) Name one device which works on this principle.
A simple electric circuit has 24 V battery and a resistor of 60 Ω. What will be the current in the circuit? The resistance of the connecting wires is negligible.
Define electric power. An electrical device of resistance R is connected across a source of voltage V and draws a current I. Derive an expression for power in terms of current and resistance.
Why is heating element wound on a long porcelain rod in a room heater.
State the reason why, in a three pin plug, the earth pin is longer and thicker than the other two.
Three 250 W heaters are connected in parallel to a 100 V supply, Calculate the resistance of each heater.
An electric bulb is rated as 100W – 250V. What information does it convey? Calculate the current through the filament of the bulb.
Compare the power used in the 2 Ω resistor in each of the following circuits:
- a 6 V battery in series with 1 Ω and 2 Ω resistors
- a 4 V battery in parallel with 12 Ω and 2 Ω resistors.
