Advertisements
Advertisements
प्रश्न
A coil is connected to a galvanometer. When the N-pole of magnet is pushed into the coil, the galvanometer deflected to the right. What deflection, if any, is observed when:
the S-pole is inserted?
Advertisements
उत्तर
When the S-pole of a magnet is inserted, the deflection of galvanometer needle will take place in left direction.
APPEARS IN
संबंधित प्रश्न
Which effect of current can be utilised in detecting a current carrying wire concealed in a wall?
Name the scientist who discovered the magnetic effect of current.
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 an anticlockwise direction, then this end is a ........... pole.
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.
Which way does the wire in the diagram below tend to move?
When the switch S is closed in the figure given below, the pointer of the galvanometer moves to the right.
If S is kept closed, will the pointer:
(a) return to zero?
(b) stay over on the right?
(c) move to the left and stay there
(d) move to and fro until S is opened
The north pole of a long bar magnet was pushed slowly into a short solenoid connected to a galvanometer. The magnet was held stationary for a few seconds with the north pole in the middle of the solenoid and then withdrawn rapidly. The maximum deflection of the galvanometer was observed when the magnet was ______.
How should the electric lamps in a building be connected so that the switching on or off in a room has no effect on other lamps in the same building?
In the Activity shown below, how do we think the displacement of rod AB will be affected if
- current in rod AB is increased
- a stronger horse-shoe magnet is used
- length of the rod AB is increased?
|
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?
Name any two appliances which works on the phenomenon of magnetic effect of electric current.
What is that instrument which can detect the presence of electric current in a circuit?
A uniform magnetic field exists in the plane of paper pointing from left to right as shown in Figure. In the field an electron and a proton move as shown. The electron and the proton experience
Edison used a ______ wire coil is a vacuum glass and discovered the first electric bulb in 1879.
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.
As shown in the diagram an aluminium rod 'AB' is suspended horizontally between the two poles of a strong horse shoe magnet in such a way that the axis of rod is horizontal and the direction of the magnetic field is vertically upward. The rod is connected in series with a battery and a key.
State giving reason:
- What is observed when a current is passed through the aluminium rod from end B to end A?
- What change is observed in a situation in which the axis of the rod 'AB' is moved and aligned parallel to the magnetic field and current is passed in the rod in the same direction?
Using an electromagnet, you can make a working model of a railway signal as shown in figure.
