Photometry D.Optom

Lux is a unit of which of the following?

• 1. Illuminance on a surface

• 1. Luminous intensity of a source

• 1. Luminous efficiency of the source of light

• Transmission coefficient of a surface

Lux is equivalent to which of the following?

• 1. 1 candela/m²

• 1. 1 lumen/cm²

• 1. 1 lumen/m²

• 1. 1 candela/cm²

Which of the following has more luminous efficiency?

• 1. 40 W fluorescent tube

• 1. 40 W bulb

• 1. Both have the same luminous efficiency

• 1. Cannot say

Solid angle is measured in

• 1.Radians

• 2. Steradians

• 3. Degrees

• 4. Minutes

The unit of luminous intensity ‘or’ illuminating power is

• 1. Lumen

• 2. Candela

• 3. Lumen/watt

• 4. None of these

The S.I. unit of luminous intensity is

• 1. Candela

• 2. Lumen

• 3. Lumen/watt

• 4. Erg/sec

The luminous flux of a light source is measured in the units of

• 1. Lumen

• 2. Candela

• 3. Lumen/watt

• 4. Ergs/sec

Light is a/an

• 1. At rest

• 2.Energy on the flow

• 3. Material that flow

• 4. Material at rest

Light is emanated from

• 1. Non-luminous bodies

• 2. Self luminous bodies

• 3. Any body

• 4. All of these

The science of measuring brightness or relative luminous intensities of light emitted by different sources using certain standards and techniques

• 1. Visible spectrum

• 2. Photometer

• 3. Visual photometry

• 4. None of these