In a material medium, when a positron meets an electron both the particles annihilate leading to the emission of two gamma ray photons. This process forms the basis of an important diagnostic procedure called
|
(a) MRI |
(b) PET |
(c) CAT |
(d) SPECT |
(b) PET
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Which of the following has the mass closest in value to that of the positron (1 a.m.u = 931 Mev)
|
(a) Proton |
(b) Electron |
(c) Photon |
(d) Neutrino |
A charge particle is free to move in an electric field. It will travel
|
(a) Always along a line of force |
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(b) Along a line of force, if its initial velocity is zero |
|
(c) Along a line of force, if it has some initial velocity in the direction of an acute angle with the line of force |
|
(d) None of the above |
The graph between intensity of light falling on a metallic plate (I) with the current (i) generated is
|
(a)
|
(b)
|
(c)
|
(d)
|
Assertion : According to classical theory, the proposed path of an electron in Rutherford atom model will be parabolic.
Reason : According to electromagnetic theory an accelerated particle continuously emits radiation.
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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. |
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(d) If assertion is false but reason is true. |
In the figure shown, the effective capacitance between the points A and B, if each has capacitance C, is
|
(a) 2C |
(b) |
(c) 5C |
(d) |
Four charges are arranged at the corners of a square ABCD, as shown in the adjoining figure. The force on the charge kept at the centre O is
|
(a) Zero |
(b) Along the diagonal AC |
|
(c) Along the diagonal BD |
(d) Perpendicular to side AB |
