(NEET-2019) NTA Solutions (2):-
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Two similar thin equi-convex lenses, of focal length f each, are kept coaxially in contact with each other such that the focal length of the combination is F1. When the space between the two lenses is filled with glycerine (which has the same refractive index (μ = 1.5) as that of glass) then the equivalent focal length is F2. The ratio F1 : F2 will be : (1)2 : 1 (2)1 : 2 (3)2 : 3 (4)3 : 4
(NEET-2019) NTA Solutions (2):- Answer(2)
A disc of radius 2 m and mass 100 kg rolls on a horizontal floor. Its centre of mass has speed of 20 cm/s. How much work is needed to stop it? (1)3 J (2)30 kJ (3)2 J (4)1 J
(NEET-2019) NTA Solutions (1):- Answer(1)
Which colour of the light has the longest wavelength? (1)Red (2)Blue (3)Green (4)Violet
(NEET-2019) NTA Solutions (1):- Answer(1) Sol. Red has the longest wavelength among the given options.
Q. In which of the following devices the eddy current effect is not used? (1)Induction furnace (2)Magnetic braking in train (3)Electromagnet (4)Electric heater
(NEET-2019) NTA Solutions (4):- Answer(4) Sol. Electric heater does not involve Eddy currents. It uses Joule’s heating effect.
In a double slit experiment when light of wavelength 400 nm was used, the angular width of the first minima formed on a screen placed 1 m away, was found to be 0.2°. What will be the angular width of the first minima, if the entire experimental apparatus is immersed in water? (μ water = 4/3)
(NEET-2019) NTA Solutions (2):-
Body A of mass 4m moving with speed u collides with another body B of mass 2m, at rest. The collision is head on and elastic in nature. After the collision the fraction of energy lost by the colliding body A is :
(NEET-2019) NTA Solutions (2):-
Ionized hydrogen atoms and alpha particles with same momenta enters perpendicular to a constant magnetic field, B. The ratio of their radii of their paths rH : rα will be : (1)2 : 1 (2)1 : 2 (3)4 : 1 (4)1 : 4
(NEET-2019) NTA Solutions (1):-
A mass m is attached to a thin wire and whirled in a vertical circle. The wire is most likely to break when: (1)the mass is at the highest point (2)the wire is horizontal (3)the mass is at the lowest point (4)inclined at an angle of 60° from vertical
BEST SOLUTION NTA Solution (3)
When a block of mass M is suspended by a long wire of length L, the length of the wire becomes (L + l). The elastic potential energy stored in the extended wire is :
Best Solution NTA Solutions (3)
