In this lighting scheme the light does not reach the surface directly from the source, maximum light is thrown upwards to the ceiling from which it is distributed all over the room by diffused reflection. The glare being reduced the resulting illumination becomes softer. It is used for decoration purposes in cinemas, theaters, and hotels etc. and in workshops where large machines and other obstructions would cause troublesome shadows if direct lighting is employed.
In this lighting scheme the total light flux is made to fall downwards directly with the help of semi-direct reflector on the working surface and also to illuminate the ceilings and walls. It is best suited to rooms with high ceilings where a high level of uniformly distributed illumination is desirable.
In this lighting scheme the light comes partly from the ceiling by diffused reflection and party direct from the source on the working surface. As it is glare free with soft shadows it is mainly used for indoor light decoration purposes.
In this lighting scheme lamps made of diffusing glass are employed which give almost equal distribution of light in all direction.
Local lighting means an intense illumination on some particular points by means of adjustable fittings. In this lighting scheme lamps are mounted in deep reflectors to avoid glare.
Specular reflection means the reflection on some in the form of a beam of light but not scattered. In this reflection, unless the eye is placed in the path of the reflected beam the viewer is unaware of the existence of light. Diffuse reflection means the reflection of light energy in the scattered form in all direction. In this reflection, the viewer can see the illuminated surface but not the light source.
Multiple Choice Question (MCQ) of Electronics page-17:241. Which of the following statement is true? a) The saturation voltage VCF of silicon transistor is more than germanium transistor. b) The saturation voltage VCE for germanium transistor is more than silicon transistor. c) The saturation voltage VCE for silicon transistor is same as that for germanium. d) The saturation voltage VCE for silicon transistor is lower than germanium transistor.
Multiple Choice Question (MCQ) of Electronics page-16:226. Which of the following statement is correct? a) Inner electrons are always present in the semiconductor. b) Bound electrons are always present in the semiconductor. c) Free electrons are always present in the semiconductor. d) Inner and bound electrons are always present in the semiconductor.
Multiple Choice Question (MCQ) of Electronics page-15:211. The materials whose electrical conductivity is usually less than 1 × 106 mho/m are a) Semiconductors b) Conductors c) Insulators d) Alloys
Multiple Choice Question (MCQ) of Electronics page-14:196. In which of the following device the base resistors are not added in the package but added externally? a) UJT b) CUJT c) PUT d) None of the above
Multiple Choice Question (MCQ) of Electronics page-13:181. The conduction in JEFT is always by the a) Majority carriers b) Minority carriers c) Holes d) Electrons e) Holes and electrons simultaneously