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### Daily Question Banks for Engineering Entrance and Board Exams

Questions
Physics
Two metallic plates A and B, each of area 5 x 10-4 m2, are placed parallel to each other at a separation of 1 cm. Plate B carries a positive charge of 33.7 x 10-12 C. A monochromatic beam of light, with photons of energy 5 eV each, starts falling on plate A at t = 0 so that 1016 photons fall on it per square meter per second. Assume that one photoelectron is emitted for every 106 incident photons. Also assume that all the emitted photoelectrons are collected by plate B and the work function of plate A remains constant at the value 2eV. Determine
(a) the number of photoelectrons emitted up to t = 10 s
(b) the magnitude of the electric field between the plates A and B at t = 10 s, and
(c) the kinetic energy of the most energetic photoelectron emitted at t = 10 s when it reaches plate B
Neglect the time taken by the photoelectron to reach plate B. Take e0 = 8.85 x 10-12 C2/N-m2

Chemistry
When propionic acid is treated with aqueous sodium bicarbonate, CO2 is liberated. The 'C' of CO2 comes from
 (a) methyl group (b) carboxylic acid group (c) methylene group (d) bicarbonate

Mathematics
The equation of the locus of the mid-points of the circle 4x2 + 4y2 - 12x + 4y + 1 = 0 that subtend an angle of 2p/3 at its centre is...............

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