The work function of a photoelectric material is 3.3 eV. The threshold frequency will be equal to
|
(a) 8 |
(b) 8 |
(c) 8 |
(d) 8 |
The work function of a photoelectric material is 3.3 eV. The threshold frequency will be equal to
|
(a) 8 |
(b) 8 |
(c) 8 |
(d) 8 |
(d) 8
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
An object approaches a convergent lens from the left of the lens with a uniform speed 5m/s and stops at the focus. The image.
Assertion : The electron in the hydrogen atom passes from energy level n = 4 to the n = 1 level. The maximum and minimum number of photon that can be emitted are six and one respectively.
Reason : The photons are emitted when electron make a transition from the higher energy state to the lower energy state.
|
(a) If both assertion and reason are true and the reason is the correct explanation of the assertion. |
|
(b) If both assertion and reason are true but reason is not the correct explanation of the assertion. |
|
(c) If assertion is true but reason is false. |
|
(d) If the assertion and reason both are false. |
Which of the following transitions in a hydrogen atom emits photon of the highest frequency
|
(a) n = 1 to n = 2 |
(b) n = 2 to n = 1 |
(c) n = 2 to n = 6 |
(d) n = 6 to n = 2 |
A convex lens forms a real image of a point object placed on its principal axis. If the upper half of the lens is painted black:
In a moving coil galvanometer, the deflection of the coil θ is related to the electrical current i by the relation
|
(a) i ∝ tanθ |
(b) i ∝ θ |
(c) i ∝ |
(d) i ∝ |
The continuous X-rays spectrum produced by an X-ray machine at constant voltage has
| (a) A maximum wavelength | (b) A minimum wavelength |
|
(c) A single wavelength |
(d) A minimum frequency |
Given below are four logic gate symbol (figure). Those for OR, NOR and NAND are respectively
|
(a) 1, 4, 3 |
(b) 4, 1, 2 |
(c) 1, 3, 4 |
(d) 4, 2, 1 |