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प्रश्न
Name the electromagnetic waves which (i) maintain the Earth’s warmth and (ii) are used in aircraft navigation.
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उत्तर
(i) Infrared rays maintain the earth’s warmth.
(ii) Microwaves are used in aircraft navigation due to their short wavelength.
संबंधित प्रश्न
What is the angle of dip at a place where the horizontal and vertical components of the Earth’s magnetic field are equal?
Choose the correct option.
A place where the horizontal component of Earth's magnetic field is zero lies at
What happens to the angle of dip as we move towards magnetic pole from magnetic equator?
A short bar magnet placed in a horizontal plane has its axis aligned along the magnetic north-south direction. Null points are found on the axis of the magnet at 14 cm from the centre of the magnet. The earth’s magnetic field at the place is 0.36 G and the angle of dip is zero. What is the total magnetic field on the normal bisector of the magnet at the same distance as the null point (i.e., 14 cm) from the centre of the magnet? (At null points, field due to a magnet is equal and opposite to the horizontal component of earth’s magnetic field.)
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.
If the inclination is θ, the horizontal component of the earth’s field is HE and the vertical component of the earth’s field is ZE, then tan(θ) is ______.
A long straight horizontal cable carries a current of 2.5 A in the direction 10° south of west to 10° north of east. The magnetic meridian of the place happens to be 10° west of the geographic meridian. The earth’s magnetic field at the location is 0.33 Gauss, and the angle of dip is zero. Locate the line of neutral points. (Ignore the thickness of the cable).
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?
At a certain place horizontal component is `sqrt(3^2)` time the vertical component. The angle of dip at this place.
Consider the plane S formed by the dipole axis and the axis of earth. Let P be point on the magnetic equator and in S. Let Q be the point of intersection of the geographical and magnetic equators. Obtain the declination and dip angles at P and Q.
