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प्रश्न
The reduction factor K of a tangent galvanometer is written on the instrument. The manual says that the current is obtained by multiplying this factor to tan θ. The procedure works well at Bhuwaneshwar. Will the procedure work if the instrument is taken to Nepal? If there is same error, can it be corrected by correcting the manual or the instrument will have to be taken back to the factory?
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उत्तर
Yes, the procedure will work if the instrument is taken to Nepal, as the current at a place can be calculated by multiplying the reduction factor K with tan θ of that place . In our case, we will take the value of tan θ of Nepal, as tan θ may vary from place to place. tan θ at any place is determined from the mathematical formula `B/B_H` , where B is the external magnetic field and `B_H` is the horizontal component of Earth's magnetic field Thus, we need not take the manual or the instrument back to the factory for correction.
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संबंधित प्रश्न
Name three elements of the earth's magnetic field which help in defining earth's magnetic field completely.
Name the electromagnetic waves which (i) maintain the Earth’s warmth and (ii) are used in aircraft navigation.
What is the angle of dip at a place where the horizontal and vertical components of the Earth’s magnetic field are equal?
Can the dip at a place be (a) zero (b) 90°?
To keep valuable instruments away from the earth's magnetic field, they are enclosed in iron boxes. Explain.
Choose the correct option.
The horizontal and vertical component of magnetic field of Earth are same at someplace on the surface of Earth. The magnetic dip angle at this place will be
Solve the following problem.
A magnet makes an angle of 45° with the horizontal in a plane making an angle of 30° with the magnetic meridian. Find the true value of the dip angle at the place.
Answer the following question regarding earth’s magnetism:
A vector needs three quantities for its specification. Name the three independent quantities conventionally used to specify the earth’s magnetic field.
Answer the following question regarding earth’s magnetism:
The earth’s field, it is claimed, roughly approximates the field due to a dipole of magnetic moment 8 × 1022 J T−1 located at its centre. Check the order of magnitude of this number in some way.
Answer the following question regarding earth’s magnetism:
Geologists claim that besides the main magnetic N-S poles, there are several local poles on the earth’s surface oriented in different directions. How is such a thing possible at all?
The earth may have even reversed the direction of its field several times during its history of 4 to 5 billion years. How can geologists know about the earth’s field in such distant past?
Interstellar space has an extremely weak magnetic field of the order of 10–12 T. Can such a weak field be of any significant consequence? Explain.
A short bar magnet of magnetic moment 5.25 × 10−2 J T−1 is placed with its axis perpendicular to the earth’s field direction. At what distance from the centre of the magnet, the resultant field is inclined at 45° with earth’s field on (a) its normal bisector and (b) its axis. Magnitude of the earth’s field at the place is given to be 0.42 G. Ignore the length of the magnet in comparison to the distances involved.
A compass needle free to turn in a horizontal plane is placed at the centre of circular coil of 30 turns and radius 12 cm. The coil is in a vertical plane making an angle of 45° with the magnetic meridian. When the current in the coil is 0.35 A, the needle points west to east.
(a) Determine the horizontal component of the earth’s magnetic field at the location.
(b) The current in the coil is reversed, and the coil is rotated about its vertical axis by an angle of 90° in the anticlockwise sense looking from above. Predict the direction of the needle. Take the magnetic declination at the places to be zero.
Which of the following independent quantities is not used to specify the earth’s magnetic field?
If the change in value of g at height h above the surface of the earth is the same as at a depth d below the surface of the earth, when both d and h are much smaller than the radius of the Earth, then which one of the following is true?
A 10-meter wire is kept in east-west direction. It is falling down with a speed of 5.0 meter/second, perpendicular to the horizontal component of earth's magnetic field of 0.30 × 10−4 weber/meter2. The momentary potential difference induced between the ends of the wire will be:
The vertical component of earth's magnetic field is zero at a place where angle of dip is
The earth's magnetic field lines resemble that of a dipole at the centre of the earth. If the magnetic moment of this dipole is close to 8 × 1022 Am2, the value of earth's magnetic field near the equator is close to ______. (radius of the earth = 6.4 × 106 m)
