Action spectrum

Q. Photosynthetic Active Radiation (PAR) has the following range of wavelengths

1. 340-450 nm
2. 400-700 nm
3. 500-600 nm
4. 450-950 nm

Q. Which of the following lights, is least effective during photosynthesis?

1. Red
2. Blue
3. Green
4. Infra-red

Q. Green light has a wavelength of

1. 400 – 450 nm
2. 500 − 580 nm
3. 660 – 720 nm
4. 720 − 800 nm

Q. The leaves of a plant appear green because these

1. Absorb and reflect green light
2. Absorb green light
3. Neither absorb nor reflect green light
4. Reflect green light

Q. Regarding assertion and reason choose the right option
Assertion [A]: Only some fraction of the total solar energy input is utilized by plants.
Reason [R]: Of the total solar radiation, only a certain spectrum is used by plants, and this region of the spectrum is called PAR.

1. Both A and R are true and R explains A
2. Both A and R are true R does not explain A
3. A is true and R is false
4. Both A and R are false

Q. Action spectrum of photosynthesis was first studied by

1. Blackman
2. Van mayer
3. Engelmann
4. Mayerhoff

Q.

During discharge in a discharge tube why do different colors are emittedif awe take different gases in the tube ?( cathode rays)

Q. Of the total incident solar radiation the proportion of PAR is:

1. More than 80%
2. About 70%
3. About 60%
4. Less than 50%

Q. The most effective wavelength of light participating in photosynthesis is

1. 450-520 nm
2. 700-760 nm
3. 660-700 nm
4. 520-560 nm

Q.

In which of the following light is the rate of photosynthesis maximum?

1. Green

2. White

3. Red

4. Blue