A metal plate weighing 750g is to be electroplated with 0.05% of its weight of silver. If a current of 0.8A is used, find the time (approx) needed for depositing the required weight of silver […]
The wavelength of kα, X-rays produced by an X-ray tube 0.76Å. The atomic number of the anode material of the tube is
Options
(a) 20 (b) 60 (c) 41 (d) 80
Correct Answer:
41
Aperture of human eye is 0.2 cm. The minimum magnifying power of a visual telescope, whose objective has diameter 100 cm is
Options
(a) 500 (b) 0.002 (c) 0.02 (d) 100
Correct Answer: […]
A battery charges a parallel plate capacitor seperated by distance(d) so that the energy (V₀) is stored in the system. A slap of dielectric constant (K) and thickness(d) is then introduced between the plates of […]
Pure Si at 300 k has equal electrons (nₑ) and hole (nh) concentrations of 1.5×10⁺¹⁶ m⁻³. Dopping by indium, nh increases to 3×10²² m⁻³. What is nₑ in doped Si?
Options
(a) 2.5×10⁹ […]
A charge Q is uniformly distributed over a large plastic plate. The electric field at point P close to centre of plate is 10Vm⁻¹. If the plastic plate is replaced by copper plate of the […]
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