Tag: magnetic force

Questions Related to magnetic force

An electron is moving vertically downwards at any place. The direction of magnetic force acting on it due to horizontal component of earth's magnetic field will be

physics magnetic fields and electromagnetism fleming's left hand rule magnetic force magnetic force on a moving charge and current carrying wire

  1. towards east

  2. towards west

  3. towards north

  4. towards south

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Correct Option: B
Explanation:

According to Fleming left hand rule, if the direction of horizontal component of earth's magnetic field is from south to north and direction of velocity of electron is downwards then the direction of the force given by the thumb is towards west.

An electron and a proton travel with equal speeds and in the same direction, at $90^o$ to a uniform magnetic field. They experience forces which are initially

physics magnetic fields and electromagnetism fleming's left hand rule magnetic force magnetic force on a moving charge and current carrying wire

  1. in opposite direction and differ by a factor of about 1840

  2. in the same direction and differ by a factor of about 1840

  3. equal in magnitude but in opposite directions

  4. identical

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Correct Option: C
Explanation:
As both of the particle having same speed and in the same field at same angle, they will be experiencing same force but in opposite direction as they are opposite in charge. 

How will be the direction of force will get changed, if the current is reversed in the conductor placed in a magnetic field?

physics magnetic effect of electric current fleming's left hand rule magnetic force magnetic force on a moving charge and current carrying wire

  1. Direction of force rotates by right angle

  2. Direction of force is reversed.

  3. Direction of force remains same

  4. Can't say

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Correct Option: B

A proton is projected horizontally eastward in a uniform magnetic field, which is horizontal and southward in direction. The proton will be deflected

physics magnetic effect of electric current fleming's left hand rule magnetic force magnetic force on a moving charge and current carrying wire

  1. upward

  2. downward

  3. northward

  4. southward

Show answer
Correct Option: B
Explanation:

By Fleming's left hand rule, taking velocity (middle finger) in east direction and magnetic field (index finger) in south direction, we get force (thumb) in vertically downward direction.

An electron enters a magnetic field at right angles to it. The direction of force acting on the electron will be

physics magnetic effect of electric current fleming's left hand rule magnetic force magnetic force on a moving charge and current carrying wire

  1. to the right.

  2. to the left.

  3. out of the page.

  4. into the page.

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Correct Option: D

Which rule determines the direction of force experienced by a current Carrying straight conductor placed in a magnetic field which is perpendicular to it.

physics magnetic effect of electric current fleming's left hand rule magnetic force magnetic force on a moving charge and current carrying wire

  1. Maxwell right hand grip rule

  2. Fleming's left hand rule

  3. Fleming's right hand rule

  4. None

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Correct Option: B
Explanation:

We considered the direction of the current and that of the magnetic field perpendicular to each other and found that the force is perpendicular to both of them. The three directions can be illustrated through a simple rule, called Flemings left-hand rule. According to this rule, stretch the thumb, forefinger and middle finger of your left hand such that they are mutually perpendicular. If the first finger points in the direction of magnetic field and the second finger in the direction of the current, then the thumb will point in the direction of motion or the force acting on the conductor.

In the statement of Fleming's left hand rule, magnetic field is represented by

physics magnetic effect of electric current fleming's left hand rule magnetic force magnetic force on a moving charge and current carrying wire

  1. thumb

  2. fore finger

  3. middle finger

  4. none

Show answer
Correct Option: B
Explanation:

The direction of the current and that of the magnetic field perpendicular to each other and found that the force is perpendicular to both of them. The three directions can be illustrated through a simple rule, called Flemings left-hand rule. According to this rule, stretch the thumb, forefinger and middle finger of your left hand such that they are mutually perpendicular. If the first finger points in the direction of magnetic field and the second finger in the direction of the current, then the thumb will point in the direction of motion or the force acting on the conductor.

In the statement of Fleming's left hand rule, what do the direction of centre finger represents

physics magnetic effect of electric current fleming's left hand rule magnetic force magnetic force on a moving charge and current carrying wire

  1. motion

  2. magnetic field

  3. current

  4. none

Show answer
Correct Option: C
Explanation:

The direction of the current and that of the magnetic field perpendicular to each other and found that the force is perpendicular to both of them. The three directions can be illustrated through a simple rule, called Flemings left-hand rule. According to this rule, stretch the thumb, forefinger and middle finger of your left hand such that they are mutually perpendicular. If the first finger points in the direction of magnetic field and the second finger in the direction of the current, then the thumb will point in the direction of motion or the force acting on the conductor.

In the statement of Fleming's left hand rule, force acting on the conductor is  is represented by

physics magnetic effect of electric current fleming's left hand rule magnetic force magnetic force on a moving charge and current carrying wire

  1. thumb

  2. fore finger

  3. middle finger

  4. none

Show answer
Correct Option: A
Explanation:

The direction of the current and that of the magnetic field perpendicular to each other and found that the force is perpendicular to both of them. The three directions can be illustrated through a simple rule, called Flemings left-hand rule. According to this rule, stretch the thumb, forefinger and middle finger of your left hand such that they are mutually perpendicular. If the first finger points in the direction of magnetic field and the second finger in the direction of the current, then the thumb will point in the direction of motion or the force acting on the conductor.

An electron is moving towards east in a magnetic field acting vertically downwards. So the electron is deflected towards:

physics magnetic effect of electric current fleming's left hand rule magnetic force magnetic force on a moving charge and current carrying wire

  1. South 

  2. North

  3. East

  4. West

Show answer
Correct Option: A
Explanation:

An electron is moving towards east in a magnetic field acting vertically downwards. So, the electron is deflected in a mutually perpendicular direction to magnetic field. Using Fleming's left hand rule it is in south direction .