Recent questions tagged olympiad

Read the passage below and answer the question given below The blue colour of the sky is due to the scattering of the sunlight by the molecules of the atmosphere. The molecules of air, such as $N_2$ and $O_2$ have sizes smaller than the wavelength of visible light. As sunlight passes through the atmosphere these molecules absorb some amount of sunlight and re-emit it. They scatter blue light of shorter wavelength more strongly than red light of stronger wavelength. When we look at the sky scattered light enters our eyes and this light contains blue light in large proportion. That is why the sky appears blue. QUESTION : The colour of the sky in the absence of the atmosphere is

asked Oct 11, 2017 by priyanka.c

1 answer

Read the passage below and answer the question given below The blue colour of the sky is due to the scattering of the sunlight by the molecules of the atmosphere. The molecules of air, such as $N_2$ and $O_2$ have sizes smaller than the wavelength of visible light. As sunlight passes through the atmosphere these molecules absorb some amount of sunlight and re-emit it. They scatter blue light of shorter wavelength more strongly than red light of stronger wavelength. When we look at the sky scattered light enters our eyes and this light contains blue light in large proportion. That is why the sky appears blue. Question : The scattering of light depends on (1) wavelength of light (2) frequency of light (3) molecules of the atmosphere (4) medium

asked Oct 11, 2017 by priyanka.c

1 answer

Tyndall effect is a phenomenon of

asked Oct 11, 2017 by priyanka.c

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The light sensitive part of the eye is

asked Oct 11, 2017 by priyanka.c

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Bifocal lenses are used by people who suffer from

asked Oct 11, 2017 by priyanka.c

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What type of lens is an air bubble inside water ?

asked Oct 11, 2017 by priyanka.c

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Name the instrument used by the opticians to measure the power of the lens directly

asked Oct 11, 2017 by priyanka.c

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An object 60 cm from a lens gives a virtual image at a distance of 20 cm in front of the lens. Is this lens converging or diverging ?

asked Oct 11, 2017 by priyanka.c

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An optically denser medium should posses greater mass density than an optically rarer medium. Is this statement true or false ?

asked Oct 11, 2017 by priyanka.c

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The main constituent of petroleum gas is

asked Oct 10, 2017 by priyanka.c

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U-235 content in natural uranium is

asked Oct 10, 2017 by priyanka.c

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One unified atomic mass is equivalent to

asked Oct 10, 2017 by priyanka.c

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Which of the statement is not correct

asked Oct 10, 2017 by priyanka.c

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Choose the correct option : The magnetic field inside a long solenoid carrying current is

asked Oct 10, 2017 by priyanka.c

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Is $R_s$ is the equivalent resistance of n resistances in series and $R_p$ is the equivalent resistance of n resistances in parallel then $\frac{R_s}{R_p}$ is

asked Oct 10, 2017 by priyanka.c

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Read the following passage and answer the question given below A parallel circuit divides the current in various components (appliances) and each component can draw current as per its appropriate operation. Separate on/off switch can be put with each component in parallel circuit. Moreover, total resistance in parallel circuit arrangement decreases and hence a stronger current can be drawn from a voltage source. In parallel combination, the equivalent resistance is lesser than the least of all the resistance. Connecting a number of resistors in parallel is like providing an equal number of paths, for the electron flow which results in a decrease in resistance. Question : Two resistors of different resistances are to be connected to a battery so as to obtain a minimum current, then the mode of connecting the resistances is

asked Oct 10, 2017 by priyanka.c

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Read the following passage and answer the question below A parallel circuit divides the current in various components (appliances) and each component can draw current as per it appropriate operation. Separate on/off switch can be put with each component in parallel circuit. Moreover, total resistance in parallel circuit arrangement decreases and hence a stronger current can be drawn from a voltage source. In parallel combination, the equivalent resistance is lesser than than the least of all the resistance. Connecting a number of resistors in parallel is like providing an equal number of paths, for the electron flow which results in a decrease in resistance. Question : A domestic circuit is always connected in ___________ so that the current supply is not disrupted even if one of the circuit goes off

asked Oct 6, 2017 by priyanka.c

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During sunset the sun appears reddish in colour because of

asked Oct 6, 2017 by priyanka.c

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A convex mirror used for rear view an automobile has radius of curvature of 3m. If a bus is located at 6m from the mirror, then the nature of this image is

asked Oct 6, 2017 by priyanka.c

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A dentist uses this mirror

asked Oct 6, 2017 by priyanka.c

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A mirror which can give real as well as virtual image is

asked Oct 5, 2017 by priyanka.c

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Which type of lens have negative power?

asked Oct 5, 2017 by priyanka.c

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For the same angle of incidence of $45 {\circ}$ the refraction angle in three transparent media A, B and C are $25^{\circ}, 30^{\circ} $ and $35^{\circ}$ respectively. In which medium is the speed of light minimum and in which medium maximum?

asked Oct 5, 2017 by priyanka.c

1 answer