[طالبه حزينه]

:mommy_cut:1 تكفون ضروري الي يعرف حل هذي الاسئله يحالها لي ضروري قبل يوم الاربعاء عندي اختبار فيها يوم الاربعاء – True or false and correct:
a) The unit of constant force K is cm. sec2.
…… …………………………………………………………………………
b) The necessary condition for simple harmonic motion in simple pendulum is θ < 0.
……………………………………………………………………………….
c) In the capillary rise, the water rises in the tube because F.Cos(θ) is maximum.
………………………………………………………………………………...
d) The contact angle (θ) independent on the surface – tension of property of a certain liquid.
………………………………………………………………………………
e) A block on the end of a spring is pulled to position x = A and released. In one full cycle of its motion, the total distance dose it travels is 2A.
………………………………………………………………………………
f) The unit of acceleration due to gravity g is N /m2
………………………………………………………………………………
g) Restoring force always directed toward the equilibrium position and the displacement from equilibrium.
………………………………………………………………………………
h) The power of a lens is the ability of the lens to refract light rays closer its surface.
………………………………………………………………………………

2 – Choose the correct answer:
1) The acceleration due to gravity is:
a) g = kΔl / m b) g = 4π2/(l/T2) c) both of a &b is correct d) there is no answer correct above.
2) The necessary condition for simple harmonic motion in simple pendulum is:
a) F = -k x b) F = k x c) θ =0 d) sin (θ) = θ

3) The contact angle (θ) depend upon
a) The surface tension property of liquid.
b) The solid surface. c) Liquid forces should be maximum. d) Liquid – solid forces must be very small.
4) The force constant is:
a) k = gΔl / m b) k = 4π2/(m/T2) c) both of a &b is correct d) there is no answer correct above.

3 – Fill the dots:
a) In the capillary rise, the water ………… in the tube because ……………… is maximum.
b) The ………………. Per unit area of the liquid surface to …………. this area.
c) The acceleration due to gravity is ………………….. with the unit ……………..
d) The water will stop rising when the ……………… balances with the ………………… in the Capillary tubes.
e) In helical spring when the mass pulled down there is an ……………….…………. On the mass acts ……………
f) The ring edges in contact with water at moment of …………….. will experience a …………….force due to surface tension.
g) The surface tension is defined as ……………………………………..
……………………………………………………………………………….
h) The surface tension defined as …………………………………………..
……………………………………………………………. Joule / m2.
i) The focal length of a (+ve) thin lens can be defined as ……………….
………………………………………………………………………………...

j) The Diopter is define as ………………………………………………….
………………………………………………………………………………..