Temperature above which a ferromagnetic substance becomes paramagnetic is called
| (a) Critical temperature | (b) Boyle's temperature |
| (c) Debye's temperature | (d) Curie temperature |
Temperature above which a ferromagnetic substance becomes paramagnetic is called
| (a) Critical temperature | (b) Boyle's temperature |
| (c) Debye's temperature | (d) Curie temperature |
(d) Curie temperature
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Einstein's photoelectric equation states that
. In this equation
refers to
|
(a) Kinetic energy of all the emitted electrons |
|
(b) Mean kinetic energy of the emitted electrons |
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(c) Maximum kinetic energy of the emitted electrons |
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(d) Minimum kinetic energy of the emitted electrons |
An electromagnetic wave of frequency v = 3.0MHz passes from vacuum into a dielectric medium with permittivity ε = 4.0 . Then
|
(a) Wavelength is doubled and the frequency remains unchanged |
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(b) Wavelength is doubled and frequency becomes half |
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(c) Wavelength is halved and frequency remains unchanged |
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(d) Wavelength and frequency both remain unchanged |
In a Wheatstone’s bridge all the four arms have equal resistance R. If the resistance of the galvanometer arm is also R, the equivalent resistance of the combination as seen by the battery is
|
(a) |
(b) R |
(c) 2R |
(d) |
A flake of glass (refractive index 1.5) is placed over one of the openings of a double slit apparatus. The interference pattern displaces itself through seven successive maxima towards the side where the flake is placed. if wavelength of the diffracted light is λ = 600nm, then the thickness of the flake is
|
(a) 2100 nm |
(b) 4200 nm |
(c) 8400 nm |
(d) None of these |
The temperature of cold junction and neutral temperature of a thermocouple are 15℃ and 280℃ respectively. The temperature of inversion is
|
(a) 295℃ |
(b) 265℃ |
(c) 545℃ |
(d) 575℃ |
Assertion : Environmental damage has increased the amount of ozone in the atmosphere.
Reason : Increase of ozone increases the amount of ultraviolet radiation on earth.
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(a) If both assertion and reason are true and the reason is the correct explanation of the assertion. |
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(b) If both assertion and reason are true but reason is not the correct explanation of the assertion. |
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(c) If assertion is true but reason is false. |
|
(d) If the assertion and reason both are false. |