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प्रश्न
i) Which principle is explained in this figure?
ii) Which rule is used to find out the direction of a force in this principle?
iii) In which machine this principle is used? Draw a diagram showing working of that machine

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उत्तर
i. A force is exerted on the current-carrying conductor in the presence of a magnetic field.
ii. The Fleming’s Left-hand Rule is used.
iii. Electric Motor
APPEARS IN
संबंधित प्रश्न
State Fleming’s left-hand rule.
State whether the following statement is true or false
The field at the centre of a long circular coil carrying current will be parallel straight lines.
When is the force experienced by a current-carrying conductor placed in a magnetic field largest?
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.
Name the rule for finding the direction of magnetic field produced by a straight current-carrying conductor.
State the form of magnetic field lines around a straight current-carrying conductor.
What is the shape of a current-carrying conductor whose magnetic field pattern resembles that of a bar magnet?
What are the various ways in which the strength of magnetic field produced by a current-carrying circular coil can be increased?
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.
List three ways in which the magnetic field strength of a current-carrying solenoid can be increased?
The diagram given below represents magnetic field caused by a current-carrying conductor which is:
(a) a long straight wire
(b) a circular coil
(c) a solenoid
(d) a short straight wire
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
The front face of a circular wire carrying current behaves like a north pole. The direction of current in this face of circular wire is:
(a) clockwise
(b) downwards
(c) anticlockwise
(d) upwards
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
In a statement of Fleming's left-hand rule, what do the following represent?
(a) direction of centre finger.
(b) direction of forefinger.
(c) direction of thumb.
Name one device whose working depends on the force exerted on a current-carrying coil placed in a magnetic field.
The force experienced by a current-carrying conductor placed in a magnetic field is the largest when the angle between the conductor and the magnetic field is:
45°
60°
90°
180°
The force exerted on a current-carrying wire placed in a magnetic field is zero when the angle between the wire and the direction of magnetic field is:
45°
60°
90°
180°
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?
State the unit of magnetic field in terms of the force experienced by a current carrying conductor placed in a magnetic field
State two ways to increase the speed of rotation of a D.C. motor.
Name and state the rule of determine the direction of force experienced by a current carrying straight conductor placed in a uniform magnetic field which is perpendicular to it.
State under what conditions force acting on a current carrying conductor which is freely suspended in a magnetic field can be maximum.
State under what conditions force acting on a current carrying conductor which is freely suspended in a magnetic field can be Zero.
The north pole of Earth’s magnet is in the ____________.
A current-carrying conductor is held in an exactly vertical direction. In order to produce a clockwise magnetic field around the conductor, the current should be passed in the conductor:
The strength of magnetic field around 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?
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?
A simple motor is made in a school laboratory. A coil of wire is mounted on an axle between the poles of a horseshoe magnet, as illustrated.

In the example above, coil ABCD is horizontal and the battery is connected as shown.
- For this position, state the direction of the force on the arm AB.
- Why does the current in the arm BC not contribute to the turning force on the coil?
Assertion (A): A magnetic field exerts a force on a moving charge in the same direction as the direction of the field itself.
Reason (R): The direction of force is given by Fleming’s left-hand rule.
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.

