Illumination & Utilization interview questions

1. A.lumens emitted per watt consumed, roughly 10–15 for incandescent, 60–100 for fluorescent and 100–200 for LED lamps
2. B.eddy currents induced by a high-frequency coil heat a conductive workpiece from within, with depth set by skin effect
3. C.luminous flux is measured in lumens; illuminance in lux equals lumens received per square metre of surface
4. D.motor runs in forward and reverse motoring and forward and reverse braking, needing a converter that can reverse both current and voltage

Answer + AI explanation with Pro

1. A.Lumen and lux
2. B.Lumen method
3. C.Induction heating
4. D.Dielectric heating

Answer + AI explanation with Pro

1. A.Lumen and lux — lighting design formula N = E·A/(F·UF·MF) giving the number of luminaires from required lux, area, utilisation and maintenance factors
2. B.Lumen and lux — lumens emitted per watt consumed, roughly 10–15 for incandescent, 60–100 for fluorescent and 100–200 for LED lamps
3. C.Lumen and lux — luminous flux is measured in lumens; illuminance in lux equals lumens received per square metre of surface
4. D.Lumen and lux — motor runs in forward and reverse motoring and forward and reverse braking, needing a converter that can reverse both current and voltage

Answer + AI explanation with Pro

1. A.force at the wheel rim needed to accelerate a train and overcome gradient and track resistance over a trapezoidal speed-time curve
2. B.lighting design formula N = E·A/(F·UF·MF) giving the number of luminaires from required lux, area, utilisation and maintenance factors
3. C.illuminance on a surface normal to the light falls with the square of its distance from a point source
4. D.stator connected in star at start, cutting line current and torque to one-third of direct-on-line values, then switched to delta near rated speed

Answer + AI explanation with Pro

1. A.Luminous efficacy
2. B.Inverse square law of illumination
3. C.Lumen and lux
4. D.Star-delta starting

Answer + AI explanation with Pro

1. A.Inverse square law of illumination — stator connected in star at start, cutting line current and torque to one-third of direct-on-line values, then switched to delta near rated speed
2. B.Inverse square law of illumination — illuminance on a surface normal to the light falls with the square of its distance from a point source
3. C.Inverse square law of illumination — heating of a non-conductive material by dielectric loss in a 10–30 MHz electric field, used for wood, plastics and food
4. D.Inverse square law of illumination — lighting design formula N = E·A/(F·UF·MF) giving the number of luminaires from required lux, area, utilisation and maintenance factors

Answer + AI explanation with Pro

1. A.lumens emitted per watt consumed, roughly 10–15 for incandescent, 60–100 for fluorescent and 100–200 for LED lamps
2. B.stator connected in star at start, cutting line current and torque to one-third of direct-on-line values, then switched to delta near rated speed
3. C.luminous flux is measured in lumens; illuminance in lux equals lumens received per square metre of surface
4. D.force at the wheel rim needed to accelerate a train and overcome gradient and track resistance over a trapezoidal speed-time curve

Answer + AI explanation with Pro

1. A.Star-delta starting
2. B.Induction heating
3. C.Luminous efficacy
4. D.Inverse square law of illumination

Answer + AI explanation with Pro

1. A.Luminous efficacy — illuminance on a surface normal to the light falls with the square of its distance from a point source
2. B.Luminous efficacy — stator connected in star at start, cutting line current and torque to one-third of direct-on-line values, then switched to delta near rated speed
3. C.Luminous efficacy — lumens emitted per watt consumed, roughly 10–15 for incandescent, 60–100 for fluorescent and 100–200 for LED lamps
4. D.Luminous efficacy — eddy currents induced by a high-frequency coil heat a conductive workpiece from within, with depth set by skin effect

Answer + AI explanation with Pro

1. A.illuminance on a surface normal to the light falls with the square of its distance from a point source
2. B.lumens emitted per watt consumed, roughly 10–15 for incandescent, 60–100 for fluorescent and 100–200 for LED lamps
3. C.heating of a non-conductive material by dielectric loss in a 10–30 MHz electric field, used for wood, plastics and food
4. D.lighting design formula N = E·A/(F·UF·MF) giving the number of luminaires from required lux, area, utilisation and maintenance factors

Answer + AI explanation with Pro

1. A.Luminous efficacy
2. B.Lumen and lux
3. C.Lumen method
4. D.Inverse square law of illumination

Answer + AI explanation with Pro

1. A.Lumen method — stator connected in star at start, cutting line current and torque to one-third of direct-on-line values, then switched to delta near rated speed
2. B.Lumen method — lighting design formula N = E·A/(F·UF·MF) giving the number of luminaires from required lux, area, utilisation and maintenance factors
3. C.Lumen method — motor runs in forward and reverse motoring and forward and reverse braking, needing a converter that can reverse both current and voltage
4. D.Lumen method — lumens emitted per watt consumed, roughly 10–15 for incandescent, 60–100 for fluorescent and 100–200 for LED lamps

Answer + AI explanation with Pro

1. A.illuminance on a surface normal to the light falls with the square of its distance from a point source
2. B.force at the wheel rim needed to accelerate a train and overcome gradient and track resistance over a trapezoidal speed-time curve
3. C.eddy currents induced by a high-frequency coil heat a conductive workpiece from within, with depth set by skin effect
4. D.motor runs in forward and reverse motoring and forward and reverse braking, needing a converter that can reverse both current and voltage

Answer + AI explanation with Pro

1. A.Luminous efficacy
2. B.Lumen method
3. C.Induction heating
4. D.Four-quadrant drive operation

Answer + AI explanation with Pro

1. A.Induction heating — lumens emitted per watt consumed, roughly 10–15 for incandescent, 60–100 for fluorescent and 100–200 for LED lamps
2. B.Induction heating — force at the wheel rim needed to accelerate a train and overcome gradient and track resistance over a trapezoidal speed-time curve
3. C.Induction heating — motor runs in forward and reverse motoring and forward and reverse braking, needing a converter that can reverse both current and voltage
4. D.Induction heating — eddy currents induced by a high-frequency coil heat a conductive workpiece from within, with depth set by skin effect

Answer + AI explanation with Pro

1. A.luminous flux is measured in lumens; illuminance in lux equals lumens received per square metre of surface
2. B.stator connected in star at start, cutting line current and torque to one-third of direct-on-line values, then switched to delta near rated speed
3. C.illuminance on a surface normal to the light falls with the square of its distance from a point source
4. D.heating of a non-conductive material by dielectric loss in a 10–30 MHz electric field, used for wood, plastics and food

Answer + AI explanation with Pro

1. A.Star-delta starting
2. B.Four-quadrant drive operation
3. C.Lumen and lux
4. D.Dielectric heating

Answer + AI explanation with Pro

1. A.Dielectric heating — motor runs in forward and reverse motoring and forward and reverse braking, needing a converter that can reverse both current and voltage
2. B.Dielectric heating — lumens emitted per watt consumed, roughly 10–15 for incandescent, 60–100 for fluorescent and 100–200 for LED lamps
3. C.Dielectric heating — eddy currents induced by a high-frequency coil heat a conductive workpiece from within, with depth set by skin effect
4. D.Dielectric heating — heating of a non-conductive material by dielectric loss in a 10–30 MHz electric field, used for wood, plastics and food

Answer + AI explanation with Pro

1. A.illuminance on a surface normal to the light falls with the square of its distance from a point source
2. B.force at the wheel rim needed to accelerate a train and overcome gradient and track resistance over a trapezoidal speed-time curve
3. C.lighting design formula N = E·A/(F·UF·MF) giving the number of luminaires from required lux, area, utilisation and maintenance factors
4. D.stator connected in star at start, cutting line current and torque to one-third of direct-on-line values, then switched to delta near rated speed

Answer + AI explanation with Pro

1. A.Tractive effort
2. B.Star-delta starting
3. C.Lumen and lux
4. D.Four-quadrant drive operation

Answer + AI explanation with Pro

1. A.Tractive effort — motor runs in forward and reverse motoring and forward and reverse braking, needing a converter that can reverse both current and voltage
2. B.Tractive effort — force at the wheel rim needed to accelerate a train and overcome gradient and track resistance over a trapezoidal speed-time curve
3. C.Tractive effort — lighting design formula N = E·A/(F·UF·MF) giving the number of luminaires from required lux, area, utilisation and maintenance factors
4. D.Tractive effort — lumens emitted per watt consumed, roughly 10–15 for incandescent, 60–100 for fluorescent and 100–200 for LED lamps

Answer + AI explanation with Pro

1. A.lighting design formula N = E·A/(F·UF·MF) giving the number of luminaires from required lux, area, utilisation and maintenance factors
2. B.luminous flux is measured in lumens; illuminance in lux equals lumens received per square metre of surface
3. C.lumens emitted per watt consumed, roughly 10–15 for incandescent, 60–100 for fluorescent and 100–200 for LED lamps
4. D.stator connected in star at start, cutting line current and torque to one-third of direct-on-line values, then switched to delta near rated speed

Answer + AI explanation with Pro

1. A.Inverse square law of illumination
2. B.Lumen and lux
3. C.Dielectric heating
4. D.Star-delta starting

Answer + AI explanation with Pro

1. A.Star-delta starting — lumens emitted per watt consumed, roughly 10–15 for incandescent, 60–100 for fluorescent and 100–200 for LED lamps
2. B.Star-delta starting — stator connected in star at start, cutting line current and torque to one-third of direct-on-line values, then switched to delta near rated speed
3. C.Star-delta starting — force at the wheel rim needed to accelerate a train and overcome gradient and track resistance over a trapezoidal speed-time curve
4. D.Star-delta starting — eddy currents induced by a high-frequency coil heat a conductive workpiece from within, with depth set by skin effect

Answer + AI explanation with Pro

1. A.heating of a non-conductive material by dielectric loss in a 10–30 MHz electric field, used for wood, plastics and food
2. B.force at the wheel rim needed to accelerate a train and overcome gradient and track resistance over a trapezoidal speed-time curve
3. C.motor runs in forward and reverse motoring and forward and reverse braking, needing a converter that can reverse both current and voltage
4. D.lighting design formula N = E·A/(F·UF·MF) giving the number of luminaires from required lux, area, utilisation and maintenance factors

Answer + AI explanation with Pro

1. A.Lumen and lux
2. B.Four-quadrant drive operation
3. C.Lumen method
4. D.Tractive effort

Answer + AI explanation with Pro

1. A.Four-quadrant drive operation — stator connected in star at start, cutting line current and torque to one-third of direct-on-line values, then switched to delta near rated speed
2. B.Four-quadrant drive operation — illuminance on a surface normal to the light falls with the square of its distance from a point source
3. C.Four-quadrant drive operation — heating of a non-conductive material by dielectric loss in a 10–30 MHz electric field, used for wood, plastics and food
4. D.Four-quadrant drive operation — motor runs in forward and reverse motoring and forward and reverse braking, needing a converter that can reverse both current and voltage

Answer + AI explanation with Pro