A star has its own light (Our SUN also one of the star). But a planet has no light of its own. It shines by reflecting the light of the sun.
23) Planets do not twinkle because
they are nearer to earth and hence we receive a greater amount of light and, therefore minor variations in the intensity are not noticeable
Related General Physics MCQ with Answers
they contain free electrons
Conductors have free electrons in valence band. There is no forbidden energy gap between valence band and conduction band. Thus the electrons can readily jump from valence band to conduction band. Thus motion of electrons implies flow of current and hence metals are good conductors.
will not rise
Since in capillary tube liquid flows against the gravity where the liquid continuosly rises in the narrow space but it is not so in any other tube of insufficient lenth.
Impulse and moment of force
Impulse means change in the momentum of a body i.e. Impulse = Ft = mv - mu The turning effect of force about the axis of rotation is called moment of force or torque. So they don't have any units... resulting no dimensions!!
momentum
1)According to newton,s 2nd law force = rate of change of momentum i.e.,momentum=m*v F= M*(D*V/DT)=M*A so it is case of m1v1 and m2v2 m1 is not = m2 hence v1 is not = v2 now Newton's 3rd law come in pictutre during impact F1=F2 ......(equal and opposite reaction) hence m1a1=m2a2 momentum1=momentum2 2)it can be a case of special relativity increase in velocity= increase in inertia = increase in enrgy then apply law of conservation of energy again newtons 3rd law 3)concider it is case of closed system between two bodies