A man is Standing on the peak of a mountain and finds that evening sun rays are nearly horizontal. At a horizontal distance of 6 km from him, its raining and he sees a beautiful rainbow. The sun rays entering water drop get refracted, reflected and refracted to form a rainbow. The red light is emitted from a drop upto a maximum angle of `42°` with respect to the incident sunlight. In front of the man there is a flat valley at a depth of 0.5 km from the mountain peak. What fraction of the complete circular arc of the rainbow is visible to the man?
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The peak value of an alternating current is 5A and its frequency is 60Hz. Find its rms value. How long will the cukrgrenQt current IS 5 A and its freq
`I_("rms")=(I_(0))/(sqrt2)=(5)/(sqrt2)A, t=(T)/(4)=(1)/(240)s`
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An inductor (L=2000mH) is connected to an AC source of peak current. What is the instantaneous voltage of the source when the current is at its peak v
Because phase difference between voltage and current is `pi//2` for pure inductor. So, Ans is zero
2 Answers 1 views
2. The old man bowed to all of us in the room. a. Who was the old man? b. Where was the old man at that time? c. Why had he come there?
This is Englih.Extracts taken from lesson genleman rio en medio please answer fastly friends
2 Answers 10 views
A man of height 1.8 m is standing in front of a wall. The sun is exactly behind him. His shadow has a length 1.5 m on the ground and 0.75 m on the wal
Correct Answer - `2.57 m `
2 Answers 4 views
The period of revolutions of Mars around th esun is 1.881 year and its mean distance from the sun is `1.524AU`. Calculate the mass of sun `(1AU=1.496x
Correct Answer - `1.998xx10^(30)kg`
2 Answers 1 views
The total luminosity of the sun is `3.9xx10^(26)W`. The mean distance of the sun from the earth is `1.496xx10^(11)m`. Calculate the value of solar con
Correct Answer - `1.688xx10^(3)Wm^(-2)`
2 Answers 1 views
A concave lens is placed in the path of convergent rays. The rays are focussed on the axis 15 cm behind the lens. Where would these rays have been foc
Correct Answer - At a distance of 10 cm behind the lens
2 Answers 1 views
A person is walking to the east at 2 km/hr and the rain drops appear to him dropping vertically downwards at `2sqrt(3)km//hr`. Find the actual velocit
Correct Answer - 4 km/hr at an angle of `30^(@)` with the vertical
2 Answers 4 views
A swimmer takes 4 second in crossing some distance in downstream and taken 6 second in upstream for same distance then find the time taken by him to c
Correct Answer - 4.8 sec
2 Answers 1 views
A man standing on a moving escalator, completes a certain distance in time `t_(1)`. If the escalator does not move then man covers this distance in ti
Correct Answer - (i)`(t_(1)t_(2))/(t_(1)+t_(2))`, (ii)`(t_(1)t_(2))/(|t_(1)-t_(2)|)`
2 Answers 3 views