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प्रश्न
Differentiate between conductors and insulators.
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उत्तर
| Sr. No. | Conductors | Insulators |
| 1. | Those substances through which electricity can flow are called conductors. | Those substances through which electricity cannot flow are called insulators. |
| 2. | Electrical resistances of conductors are very low. | Electrical resistances of insulators are infinitely very high. |
| 3. | They contain a large number of free electrons. | They do not contain free electrons. |
| 4. | Generally, metals are conductors. E.g., silver, copper, aluminium. | Generally, non-metals are insulators. E.g., wood, rubber, plastic. |
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संबंधित प्रश्न
Consider a circular loop of wire lying in the plane of the table. Let the current pass through the loop clockwise. Apply the right-hand rule to find out the direction of the magnetic field inside and outside the loop.
State Fleming’s left-hand rule.
State the rule to determine the direction of a force experienced by a current-carrying straight conductor placed in a magnetic field which is perpendicular to it.
Observe the following figure:
If the current in the coil A is changed, will some current be induced in the coil B? Explain.
What concealed do you get from the observation that a current-carrying wire deflects a compass needle placed near it?
What is the shape of a current-carrying conductor whose magnetic field pattern resembles that of a bar magnet?
Draw a sketch to show the magnetic lines of force due to a current-carrying straight conductor.
State and explain the Clock face rule for determining the polarities of a circular wire carrying current.
Name any two factors on which the strength of magnetic field produced by a current-carrying solenoid depends. How does it depend on these factors?
What is a solenoid? Draw a sketch to show the magnetic field pattern produced by a current-carrying solenoid.
The magnetic field lines in the middle of the current-carrying solenoid are?
(a) circles
(b) spirals
(c) parallel to the axis of the tube
(d) perpendicular to the axis of the tube
A current-carrying straight wire is held in exactly vertical position. If the current passes through this wire in the vertically upward direction, what is the direction of magnetic field produced by it? Name the rule used to find the direction of magnetic field.
A current-carrying conductor is held in exactly vertical direction. In order to produce a clockwise magnetic field around the conductor, the current should passed in the conductor:
(a) from top towards bottom
(b) from left towards right
(c) from bottom towards top
(d) from right towards left
A current-carrying conductor is placed perpendicularly in a magnetic field. Name the rule which can be used to find the direction of force acting on the conductor.
State two ways to increase the force on a current-carrying conductor in a magnetic field.
Name one device whose working depends on the force exerted on a current-carrying coil placed in a magnetic field.
State Fleming's left-hand rule. Explain it with the help of labelled diagrams.
A current flows in a wire running between the S and N poles of a magnet lying horizontally as shown in Figure below:
The force on the wire due to the magnet is directed:
fron N to S
from S to N
vertically downwards
vertically upwards
A horizontal wire carries a current as shown in Figure below between magnetic poles N and S:
Is the direction of the force on the wire due to the magnet:
(a) in the direction the current
(b) vertically downwards
(c) opposite to the current direction
(d) vertically upwards
In the simple electric motor of figure given below, the coil rotates anticlockwise as seen by the eye from the position X when current flows in the coil
Is the current flowing clockwise or anticlockwise around the coil when viewed from above?
If the current in a wire is flowing in the vertically downward direction and a magnetic field is applied from west to east, what is the direction of force in the wire?
Two coils A and B of insulated wire are kept close to each other. Coil A is connected to a galvanometer while coil B is connected to a battery through a key. What would happen if:
a current is passed through coil B by plugging the key?
Explain your answer mentioning the name of the phenomenon involved.
State the unit of magnetic field in terms of the force experienced by a current carrying conductor placed in a magnetic field
A flat coil ABCD is freely suspended between the pole of U-shaped permanent magnet with the plane of coil parallel to the magnetic field.
What happens when a current is passed in the coil?
State Fleming’s left-hand rule.
A flat coil ABCD is freely suspended between the pole pieces of a U-shaped permanent magnet with the plane of coil parallel to the magnetic field.
When will the couple acting on the coil be
- maximum
- minimum?
The following diagram shows two parallel straight conductors carrying the same current. Copy the diagram and draw the pattern of the magnetic field lines around them showing their directions. What is the magnitude of the magnetic field at a point 'X' which is equidistant from the conductors? Give justification for your answer.
State whether a magnetic field is associated or not around a static charge.
State under what conditions force acting on a current carrying conductor which is freely suspended in a magnetic field can be Zero.
The shape of the magnetic field lines produced by a current-carrying conductor is ____________.
Which of the following factors affect the strength of force experience by current-carrying conduct in a uniform magnetic field?
A magnetic field directed in north direction acts on an electron moving in east direction. The magnetic force on the electron will act ____________.
Describe the activity that shows that a current-carrying conductor experiences a force perpendicular to its length and the external magnetic field. How does Fleming’s left-hand rule help us to find the direction of the force acting on the current carrying conductor?
Assertion (A): A current carrying straight conductor experiences a force when placed perpendicular to the direction of magnetic field.
Reason (R): The net charge on a current carrying conductor is always zero.
A copper conductor is placed over two stretched copper wires whose ends ate connected to a D.C. supply as shown in the diagram.
- What should be the magnetic poles at the points A and B lying on either side of the conductor to experience the force in the upward direction?
- Name the law used to find these polarities.
