When light travels from an optically denser medium to a rarer medium, why does the critical angle of incidence depend on the colour of light?
[9] Ray Optics and Optical Instruments
Chapter: [9] Ray Optics and Optical Instruments
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When a wave is propagating from a rarer to a denser medium, which characteristic of the wave does not change and why?
[9] Ray Optics and Optical Instruments
Chapter: [9] Ray Optics and Optical Instruments
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A point-object is placed on the principal axis of convex spherical surface of radius of curvature R, which separates the two media of refractive indices n1 and n2 (n2>n1). Draw the ray diagram and deduce the relation between the distance of the object (u), distance of the image (v) and the radius of curvature (R for refraction to take place at the convex spherical surface from rarer to denser medium.
[9] Ray Optics and Optical Instruments
Chapter: [9] Ray Optics and Optical Instruments
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A potential difference of 220 V is maintained across 12000 Ω rheostat. Then voltmeter V has a resistance of 6000 Ω and point C is at one fourth the distance from a to b. Then the reading of voltmeter is ______.
[3] Current Electricity
Chapter: [3] Current Electricity
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If one penetrates a uniformly charged spherical cloud, electric field strength ______.
[1] Electric Charges and Fields
Chapter: [1] Electric Charges and Fields
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The electric field inside a spherical shell of uniform surface charge density is ______.
[1] Electric Charges and Fields
Chapter: [1] Electric Charges and Fields
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On decreasing the distance between the plates of a parallel plate capacitor, its capacitance ______.
[2] Electrostatic Potential and Capacitance
Chapter: [2] Electrostatic Potential and Capacitance
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Capacity of a parallel plate condenser can be increased by ______.
[2] Electrostatic Potential and Capacitance
Chapter: [2] Electrostatic Potential and Capacitance
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When a potential difference V is applied across a conductor at a temperature T, the drift velocity of electrons is proportional to ______.
[3] Current Electricity
Chapter: [3] Current Electricity
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A metal wire is subjected to a constant potential difference. When the temperature of the metal wire increases, the drift velocity of the electron in it ______.
[3] Current Electricity
Chapter: [3] Current Electricity
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What is the suitable material for electric fuse?
[3] Current Electricity
Chapter: [3] Current Electricity
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When potential difference is applied across an electrolyte, then Ohm’s law is obeyed at ______.
[3] Current Electricity
Chapter: [3] Current Electricity
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Magnetic dipole moment of a rectangular loop is ______.
[4] Moving Charges and Magnetism
Chapter: [4] Moving Charges and Magnetism
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Assertion: The earth¢s magnetic field is due to iron present in its core.
Reason: At a high temperature magnet losses its magnetism.
[5] Magnetism and Matter
Chapter: [5] Magnetism and Matter
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A dip circle is so set that its needle moves freely in the magnetic meridian. In this position, the angle of dip is 40º. Now the dip circle is rotated so that the plane in which the needle moves makes an angle of 30º with the magnetic meridian. In this position, the needle will dip by an angle ______.
[5] Magnetism and Matter
Chapter: [5] Magnetism and Matter
Concept: undefined >> undefined
The time period of oscillation of a magnet in a vibration magnetometer is 1.5 sec. The time period of oscillation of another magnet similar in size, shape and mass but having 1/4 magnetic moment than that of the 1st magnet oscillating at the same place will be ______.
[5] Magnetism and Matter
Chapter: [5] Magnetism and Matter
Concept: undefined >> undefined
Current I is flowing in a coil of area A and number of turns is N, then magnetic moment of the coil in M equal to ______.
[5] Magnetism and Matter
Chapter: [5] Magnetism and Matter
Concept: undefined >> undefined
On cutting a solenoid in half, the field lines remain ...A..., emerging from one face of the solenoid and entering into the other face. Here, A refers to ______.
[5] Magnetism and Matter
Chapter: [5] Magnetism and Matter
Concept: undefined >> undefined
A temporary magnet is made of ______.
[5] Magnetism and Matter
Chapter: [5] Magnetism and Matter
Concept: undefined >> undefined
The primary origin of magnetism lies in ______.
[5] Magnetism and Matter
Chapter: [5] Magnetism and Matter
Concept: undefined >> undefined
