When yellow light is incident on a surface, no electrons are emitted while green light can emit. If red light is incident on the surface, then
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(a) No electrons are emitted |
|
(b) Photons are emitted |
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(c) Electrons of higher energy are emitted |
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(d) Electrons of lower energy are emitted |
(a) No electrons are emitted
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Which of the following is wrong statement
|
(a) An emf can be induced between the ends of a straight conductor by moving it through a uniform magnetic field |
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(b) The self induced emf produced by changing current in a coil always tends to decrease the current |
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(c) Inserting an iron core in a coil increases its coefficient of self induction |
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(d) According to Lenz's law, the direction of the induced current is such that it opposes the flux change that causes it |
The energy required to knock out the electron in the third orbit of a hydrogen atom is equal to
|
(a) 13.6 eV |
(b) + |
(c) - |
(d) - |
In given figure, the potentiometer wire AB has a resistance of 5 W and length 10 m. The balancing length AM for the emf of 0.4 V is
|
(a) 0.4 m |
(b) 4 m |
(c) 0.8 m |
(d) 8 m |
Three equal resistances each of value R are joined as shown in the figure. The equivalent resistance between M and N is
|
(a) R |
(b) 2R |
(c) |
(d) |
The bluish colour of water in deep sea is due to:
Nucleus of an atom whose atomic mass is 24 consists of
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(a) 11 electrons, 11 protons and 13 neutrons |
(b) 11 electrons, 13 protons and 11 neutrons |
|
(c) 11 protons and 13 neutrons |
(d) 11 protons and 13 electrons |
The maximum peak to peak voltage of an AM wire is 24 mV and the minimum peak to peak voltage is 8 mV. The modulation factor is
|
(a) 10% |
(b) 20% |
(c) 25% |
(d) 50% |
