- AD
- BS
- CA
- DZ
Explanation:
The mass number (A) is the number of nucleons, which is the total number of protons and neutrons in the nucleus of an atom.
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The plane faces of two identical plano-convex lenses each having focal length of 40 cm are pressed against each other to form a usual convex lens. The distance from this lens, at which an object must be placed to obtain a real, inverted image with magnification one is
|
(a) 80 cm |
(b) 40 cm |
(c) 20 cm |
(d) 162 cm |
Light of wavelength 4000 Å falls on a photosensitive metal and a negative 2V potential stops the emitted electrons. The work function of the material (in eV) is approximately (h = 6.6 ![]()
|
(a) 1.1 |
(b) 2.0 |
(c) 2.2 |
(d) 3.1 |
Two metallic plates A and B, each of area 5 ´ 10–4m2 are placed parallel to each other at a separation of 1 cm. Plate B carries a positive charge of 33.7 pc. 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 2 eV. Electric field between the plates at the end of 10 seconds is
|
(a) 2 × 103 N/C |
(b) 103 N/C |
(c) 5 × 103 N/C |
(d) Zero |
Light of wavelength 5000 Å falls on a sensitive plate with photoelectric work function of 1.9 eV. The kinetic energy of the photoelectron emitted will be
|
(a) 0.58 eV |
(b) 2.48 eV |
(c) 1.24 eV |
(d) 1.16 eV |
The work done in bringing a 20 coulomb charge from point A to point B for distance 0.2m is 2J. The potential difference between the two points will be (in volt)
|
(a) 0.2 |
(b) 8 |
(c) 0.1 |
(d) 0.4 |