NDA PHYSICS QUIZ - 31

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Question 1:

The water proof properties of the materials is due to the property of_____________

Question 2:

A grasshopper can jump maximum distance of 1.6 m. It spends negligible time on the ground. How far can it go in 10 seconds -

Question 3:

What is the change in momentum of a car of mass 800 kg when its speed increases from 72 km/h to 90 km/h uniformly ?

Question 4:

A cricket ball of mass 150 g is moving with a velocity of 12 m/s and is hit by a bat so that the ball is turned back with a velocity of 20 m/s. The force of bat acts for 0.01 s on the ball. The average force exerted by the bat on the ball is-

Question 5:

A force of 50 dynes is acted on a body of mass 5 g which is at rest for an interval of 5 seconds, then the impulse created will be –

Question 6:

What is the reason for the small air bubbles in the water collected in a glass vessel to shine with a silvery luster?

Question 7:

On which principle does a periscope work?

Question 8:

At what angle should two plane mirrors be placed to obtain three images of an object?

Question 9:

An object is placed at a distance of 60 cm from a concave mirror. What should be the focal length of the concave mirror to get its magnification of 1/2?

Question 10:

A ball is thrown vertically upwards. Which of the following plots represents the speed-time graph of the ball during its flight if the air resistance is not ignored?