The Illumination at Various Points on a Horizontal Surface Illuminated

Q11: Filament lamps operate normally at a power

Q12: ---------------------is widely used in large industrial plants

Q13: Illumination of one lumen per sq. metre

Q14: On which of the following factors dies

Q15: From the following refrigerants, which is one

Q17: For normal reading the illumination level required

Q18: ...... is a cold cathode lamp.<br>A)fluorescent lamp<br>B)neon

Q19: The refrigerants which are first cooled by-----------------refrigerants

Q20: Which of the following lamps is the

Q21: The unit of luminous flux is .<br>A)watt/m²<br>B)lumen<br>C)lumen/m²<br>D)watt