Advertisements
Advertisements
Question
Answer the following question:
State the effect on the magnetic needle in Oersted’s experiment when:
(a) the current is passed through the wire.
(b) the current through the wire is increased
(c) the current through the wire is reversed.
Advertisements
Solution
- When a current is passed through the wire, the magnetic needle gets deflected.
- When the current through the wire is increased, the deflection of the magnetic needle increases.
- When the current through the wire is reversed, the magnetic needle is deflected in the opposite direction.
APPEARS IN
RELATED QUESTIONS
Do you think an electromagnet can be used for separating plastic bags from a garbage heap? Explain.
Which effect of current can be utilised in detecting a current carrying wire concealed in a wall?
Fill in the following blank with suitable words:
The magnetic effect of a coil can be increased by increasing the number of ........... increasing the ........... or inserting an ........... core.
Fill in the following blank with suitable words:
If a coil is viewed from one end, and the current flows in a clockwise direction, then this end is a ........... pole.
What is Maxwell's corkscrew rule? For what purpose is if used?
If the direction of electric current in a solenoid when viewed from a particular end is anticlockwise, then this end of solenoid will be:
(a) west pole
(b) south pole
(c) north pole
(d) east pole
The direction of current flowing in the coil of an electromagnet at its two ends X and Y are as shown below:
What is the polarity of end X?
What is the polarity of end Y?
Name and state the rule which you have used to determine the polarities.
Write the correct option by observing the figures.

Draw magnetic field lines produced around a straight current carrying conductor passing through a cardboard. How will the strength of the magnetic field change when the point where magnetic field is to be determined is moved away from the conductor?
What is that instrument which can detect the presence of electric current in a circuit?
A magnetic compass shows a deflection when placed near a current carrying wire. How will the deflection of the compass get affected if the current in the wire is increased? Support your answer with a reason.
Unscramble the following words:
HTRCO
Edison used a ______ wire coil is a vacuum glass and discovered the first electric bulb in 1879.
What do you mean by the magnetic effect?
A wire with green insulation is usually the live wire of an electric supply.
The figure given below shows the magnetic field around the conductor. Study it and answer the questions:

- What changes are caused by increasing current?
- What do you see when the magnetic needle is kept a little away from the wire?
- In the second part of the figure, the iron filings arrange themselves in a circular manner around the wire. Why does this happen?
A student was asked to perform an experiment to study the force on a current carrying conductor in a magnetic field. He took a small aluminium rod AB, a strong horse shoe magnet, some connecting wires, a battery and a switch and connected them as shown. He observed that on passing current, the rod gets displaced. On reversing the direction of current, the direction of displacement also gets reversed. On the basis of your understanding of this phenomenon, answer the following questions:

- Why does the rod get displaced on passing current through it?
- State the rule that determines the direction of the force on the conductor AB.
-
- If the U-shaped magnet is held vertically and the aluminium rod is suspended horizontally with its end B towards due north, then on passing current through the rod from B to A as shown, in which direction will the rod be displaced?
- Name any two devices that use current carrying conductors and magnetic fields.
OR
Draw the pattern of magnetic field lines produced around a current carrying straight conductor held vertically on a horizontal cardboard. Indicate the direction of the field lines as well as the direction of current flowing through the conductor.
