Description : The striving of two or more individuals for the same object a). Allelopathy b). Competition c). Co-operation d). None of these
Last Answer : b). Competition
Description : Auto allelopathy existed in a). Wheat b). alfaalfa c). cowpea d). all
Last Answer : d). all
Description : The term, allelopathy came into exis tence in a). 1937 AD b). 500 BC c). 1974 AD d). 1832 AD
Last Answer : a). 1937 AD
Description : The term, allelopathy was given by a). Rice b). Molisch c). Decondole d). Democritus
Last Answer : b). Molisch
Description : .In functional allelopathy a). Toxic substances are released as such from the plants b). A precursor is released and is converted into active substances by some microorganisms c). No release of any toxic substance d). release of nitrogen from nodule of legume takes place
Last Answer : b). A precursor is released and is converted into active substances by some microorganisms
Description : Which crop exhibit direct allelopathy? a). Sorghum b). Maize c). Lentil d). Alfalfa
Last Answer : a). Sorghum
Description : . A crop has residual allelopathy on wheat a). Rice b). Lentil c). Maize d). Sorghum
Last Answer : b). Lentil
Description : .Which among the following crops ex hibits allo-allelopathy? a).Maize b). Sorghum c). Rye d). All
Last Answer : d). All
Description : Continuous cropping of which legume crop cause auto allelopathy? a). Chickpea b). Alfa-alfa c). Cowpea d). Pigeonpea
Last Answer : b). Alfa-alfa
Description : The term allelopathy was given by a). Rice (1974) b). Molisch (1937) c). Decondole (1832) d). Molisch (1930)
Last Answer : b). Molisch (1937)
Description : Factors affecting weed-crop interference are a). Period of weed growth b). Soil and climate influence c). Plant species effects d). All
Description : Hans Molish is associated with a). Competition b). Eutrophication c). Allelomediation d). Allelopathy
Last Answer : d). Allelopathy
Description : Multiple resistance is the phenomenon in which a weed is resistant to two or more herbicides having a). same mechanisms of action b). different mechanisms of action c). same chemistry d). different chemistry
Last Answer : b). different mechanisms of action
Description : A period in the ontogeny of crop at which maximum crop weed competition occurs is called a). Economic threshold b). Gain threshold c). Competitive threshold d). None
Last Answer : d). None
Description : Critical period of crop weed competition in sugarcane is a). 30-40 days b). 30-120 days c). 10-40 days d). 15-30 days
Last Answer : b). 30-120 days
Description : The period at which maximum crop weed competition occurs is a). Critical period b). Dormancy c). Flaming d).Threshold
Last Answer : a). Critical period
Description : Struggle for survival and existence is called a). Critical period b). Competition c). Dormancy d). Persistence
Description : Wheat and bajra have critical period of crop-weed competition a).10-20 days b).15-30 days c). 30-45 days d). 20-40 days
Last Answer : c). 30-45 days
Description : Intra-specific competition is between a). Plants of the cultivated species and weed species b). Plants of the same weed species c). Plants of the different weed species d). None of the above
Last Answer : b). Plants of the same weed species
Description : In which weed seeds mature after uproot ing the plant? a). Stellaria media (Chick weed) b). Portulaca oleracea c). Both a and b d). None of these
Last Answer : c). Both a and b
Description : A weed producing > 1 lakh seeds/plant a). Amaranthus sp b). Portulaca sp c). Both a and b d). Cascutta sp
Description : . Which are required during trialling to ensure that the effectiveness of the her bicide is tested against all pests a). Plant pathologists b). Entomologists c). Both Plant pathologists and Ento mologists d). None
Last Answer : c). Both Plant pathologists and Ento mologists
Description : The phenomenon of interference demonstrates the fact that :
Last Answer : The phenomenon of interference demonstrates the fact that : A. light possesses transvers wave ... particle nature D. light possesses wave nature
Description : The Himalayan Range is very rich in species diversity. Which one among the following is the most appropriate reason -for this phenomenon? [CSAT 2011] (a) It has a high rainfall that supports ... Exotic and invasive species have not been introduced in this region (d) It has less human interference
Last Answer : Ans: (b)
Description : Production of beats is a result of the phenomenon of (a) Resonance (b) Interference (c) Reflection (d) Superposition
Last Answer : Ans:(b)
Description : Which phenomenon is responsible for the echo of sound wave? (1) Reflection (2) Refraction (3) Interference (4) Polarization
Last Answer : (1) Reflection Explanation: Reflection of sound waves off of surfaces lead to one of two phenomena - an echo or a reverberation. The echo is produced due to hitting of the sound waves with the ... reflected sound wave reaches the ear more than 0.1 seconds after the original sound wave was heard.
Description : The phenomenon which causes mirage is – (1) Interference (2) Diffraction (3) Polarisation (4) Total internal reflection
Last Answer : (4) Total internal reflection Explanation: Mirage is caused by total internal reflection in deserts where due to heating of the earth, refractive index of air near the surface of earth becomes lesser than ... ray of light coming from a distant object gets refracted from a denser to a rarer medium.
Description : Which of the following phenomenon helps to conclude that light is a transverse wave? (1) interference (2) diffraction (3) polarization (4) refraction
Last Answer : (3) polarization Explanation: The phenomena of interference and diffraction of light were successful beyond doubt to prove that light is a form of wave. But they failed to decide whether light ... light is a transverse wave was established only after the discovery of the phenomenon of polarization.
Description : Sir C.V. Raman was awarded Nobel Prize for his work connected with which of the following phenomenon of radiation? (1) Scattering (2) Diffraction (3) Interference (4) Polarization
Last Answer : (1) Scattering Explanation: Sir C.V. Raman was awarded Nobel Prize for his work scattering of radiation. Sir Chandrashekhara Venkata Raman was an Indian physicist born in the former Madras Province in India.
Description : Light waves projected on oil surface show seven colours due to the phenomenon of (1) polarisation (2) refraction (3) reflection (4) interference
Last Answer : (4) interference Explanation: In physics, interference is a phenomenon in which two waves superpose to form a resultant wave of greater, lower, or the same amplitude.
Description : What is the phenomenon which established the transverse nature of light? (1) Reflection (2) Interference (3) Diffraction (4) Polarisation
Last Answer : (4) Polarisation Explanation: The phenomena which proves the transverse nature alight is polarization. Since the intensity of polarized light on passing through a tourmaline crystal changes, ... waves. Transverse waves are waves that are oscillating perpendicularly to the direction of propagation
Description : Optical fibres are based on the phenomenon of – (1) Interference (2) Dispersion (3) Diffraction (4) Total Internal Reflection
Last Answer : (4) Total Internal Reflection Explanation: An optical fiber (or optical fibre) is a flexible, transparent fiber made of glass (Silica) or plastic, slightly thicker than a human hair. It functions as a ... is kept in the core by total internal reflection. This causes the fiber to act as a waveguide.
Description : The phenomenon of light associated with the appearance of blue colour of the sky is – (1) Interference (2) Reflection (3) Refraction (4) Scattering
Last Answer : (4) Scattering Explanation: During daylight, the sky appears to be blue because air scatters blue sunlight more than it scatters red. At night, the sky appears to be a mostly dark surface ... day sky is a result of scattering, which is dominated by a smallparticle limit called Rayleigh scattering.
Description : Endoscopy, a technique used to explore the stomach or other inner parts of the body, is based on the phenomenon of (a) Total internal reflection (b) Interference (c) Diffraction (d) Polarisation
Last Answer : Ans: ( a ) Total internal reflection
Description : Newton’s light illustrate the phenomenon of (a) Interference (b) Diffraction (c) Dispersion (d) Polarisation
Last Answer : (a) Interference
Description : Which of the following phenomenon produces colors in soap bubble? (a) Interference (b) Diffraction (c) Polarization (d) Dispersion
Description : __________ of the following phenomenon cannot be explained on the particle nature of light. A. Photo Electric Effect B. Compton’s Effect C. Pair Production D. Interference
Last Answer : A. Photo Electric Effect
Description : Interference of light is evidence that : A. The speed of light is very large B. light is a transverse wave C. light is electromagnetic in character D. Light is a wave phenomenon
Last Answer : D. Light is a wave phenomenon
Description : Which of the following best explains the phenomenon of forgetting? Options: A) The passage of time B) The phenomenon of reminiscence C) The phenomenon of interference D) Repression
Last Answer : C) The phenomenon of interference
Description : Which phenomenon is responsible for the echo of sound wave? (1) Reflection (2) Refraction (3) Interference (4) Polarisation
Last Answer : Reflection
Description : What is the phenomenon which established the transverse nature of light ? (1) Reflection (2) Interference (3) Diffraction (4) Polarisation
Last Answer : Polarisation
Description : Which of the following phenomenon helps to conclude that light is a transverse wave? (1) interference (2) diffraction (3) polarisation (4) refraction
Last Answer : polarisation
Description : The phenomenon which causes mirage is (1) Interference (2) Diffraction (3) Polarisation (4) Total internal reflection
Last Answer : Total internal reflection
Description : The phenomenon of light associated with the appear-ance of blue colour of the sky is (1) Interference (2) Reflection (3) Refraction (4) Scattering
Last Answer : Scattering
Description : Optical fibres are based on the phenomenon of (1) Interference (2) Dispersion (3) Diffraction (4) Total Internal Reflection
Last Answer : Total Internal Reflection
Description : Prohexadione calcium a plant growth regu lator affect efficacy of which of the following herbicides in peanut a). acifluorfen b). bentazon c). imazethapyr d). None
Description : Allelochemicals are mostly present in which of the following plant parts a). Flowers and fruits b). Leaves and stems c). Roots d). All
Description : Typically pre-plant soil incorporated herbi cide a). Fluchloralin b). Trifluralin c). EPTC d). All of these
Last Answer : d). All of these
Description : Important quality of bioagents a). Attack only host plant b). Free from predators/parasites and quick adoption to new environment c). Able to kill reproductive parts of weed d). All of these
Description : Which of the following is a monocot weed but broad-leaved plant? a). Eichhornia crasipus b). Commelina banghalensis c). Cynnotis axillaris d). All of these