When a monochromatic point source of light is at a distance of `0.2` m from a photoelectron cell the cut off voltage and the saturation currect are respectively `0.6V` and `18.0 mA` if the same is plased `0.6 m` away from the photoelectric cell , then
A
the stopping potential will be `0.2Volt`
B
the stopping potential will be `0.6 Volt`
C
the stopping potential will be `6.0 Volt`
D
the stopping potential will be `2.0 Volt`
Text Solution
Verified by Experts
The correct Answer is:
B, D
Since the stopping potential depands on the frequency and not on the intensity and the source is same , the stopping potential remain unaffected . The sqatutation currect depends on the intensity of incident light on the cuthode of the photocell which in turn depends on the distance of the source from the cathode the intensity (i() of lioght is inversely propotional to the square of the distance between the light source and photcell `1 prop (1)/(r^(2))` and saturation currect `prop 1` `rArr Saturation Currect prop (1)/(r^(2))` `rArr ((Sataration Currect)_(fanal)/((Sataration Currect) _(mital) = (r_(initial)^(2))/(r_(final)^(2))` `rArr (Saturation Currect)_(final) = (0.2 xx 0.2)/(0.6 xx 0.6) xx 18 = 2mA`
SUNIL BATRA (41 YEARS IITJEE PHYSICS)|Exercise Comprehension Based Questions|2 Videos
MOVING CHARGES AND MAGNETISM
SUNIL BATRA (41 YEARS IITJEE PHYSICS)|Exercise MCQs(d )|1 Videos
Similar Questions
Explore conceptually related problems
When a monochromatic point source of light is at a distance of 0.2 m from a photoelectric cell, the cut off voltage and the saturation current are respectively 0.6 V and 18.0 mA. If the same source is placed 0.6 m away from the photoelectric cell, then (a) the stopping potential will be 0.2 V (b) the stopping potential will be 0.6 V (c ) the saturation current will be 6.0 mA (d) the saturation current will be 2.0 mA
when a monochromatic point source of light is at a distance 0.2 m from a photoelectric cell, the saturation current and cut-off voltage are 12.0 mA and 0.5 V. If the same source is placed 0.4 m away from the photoelectric cell, then the saturation current and the stopping potential respectively are
When a monochromatic source of light is at a distance of 0.2 m from a photocell, the stopping potential (cut off voltage) and the saturation current are found to be respectively 1 V and 27 mA. If the same source is placed at a distance 0.6 m from the cell, then
When a point source of light is at a distance of 50 cm from a photoelectric cell , the cut-off voltage is found to be V_(0) . If the same source is placed at a distance of 1 m from the cell , then the cut-off voltage will be
When a point source of light is at a distance of one metre from a photo cell , the cut off voltage is found to be V . If the same source is placed at 2 m distance from photo cell , the cut off voltage will be
When a point source of light is at a distnace of 1 m from a photo cell, the cut off voltage is is found to be V. if the same source is placed at 3m distance from photo cell, the cut of voltage will be
A source of light is placed at a distance of 1 m from a photo cell and the cut off potential is found to be 5 V. If the source is kept at 1.5 m from the cell, then the cut off potential will be
A source of light is placed at a distance of 1m. From a photocell and the cut off potential is found to be V_0. If the distance is doubled what will be the cut off potential?
SUNIL BATRA (41 YEARS IITJEE PHYSICS)-MODERN PHYSICS-MCQ (One Correct Answer
