Advertisements
Advertisements
Question
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.
Advertisements
Solution
Some of the questions can be
- Why does the nail attract the pins?
- What will happen if we connect more cells in the circuit?
- What will happen if we use some other material like a straw in place of the nail?
- What will happen if we wrap the wire on the nail more tightly?
APPEARS IN
RELATED QUESTIONS
Why does the connecting cord of an electric heater not glow hot while the heating element does?
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.
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).
What is overloading?
Right or wrong sentence.
Live wire and neutral wires have a 220 V potential difference.
Which of the following is correct?
Assertion: Bending of wire decreases the resistance of the electric wire.
Reason: The resistance of a conductor depends on length, thickness, nature of material and temperature of the conductor.
Name a few appliances which work on the basis of the heating effect of current.
Two students decided to investigate the effect of water and air on iron object under identical experimental conditions. They measured the mass of each object before placing it partially immersed in 10 ml of water. After a few days, the object were removed, dried and their masses were measured. The table shows their results.
| Student | Object | Mass of Object before Rusting in g |
Mass of the coated object in g |
| A | Nail | 3.0 | 3.15 |
| B | Thin plate | 6.0 | 6.33 |
What might be the reason for the varied observations of the two students?
State the law that explains the heating effect of current with respect to the measurable properties in an electrical circuit.
