Std 7 Physics First Semester 2020

                Enfant India International school

Class 7^th                          Sub-Physics.                       Marks 40    ¹

^{1. Fill in the blanks :                                  (1×5=5)}

^{(A)  A --------- can be used to measure the volume of an irregular solid.}

^{(B) The SI unit of density of a substance is ____________}

^{(C) The SI unit  of speed is _______}

^{(D) Density of water is ___________kg/m3}

^{(D) Speed of cars is usually measured in the unit __________}

^{(E) Yellow, magenta and ____________ are three secondary colours.}

^{2. Give one word for the following.         (1×5=5)}

^{(A) A ray of light travelling towards the mirror.}

^{(B) Angle between normal and the reflected ray .}

^{(C) Energy possessed by object in motion.}

^{(D) Energy used to run various electrical and electronic appliances.}

^{(E) The distance covered by an object in unit time .}

^{3. Match the following:                             (1×5 =5)}

^{A.                                                        B}

^{1 Moving object.                         (a) Heat energy}

^{2. Water stored in a dam          (b) kinetic energy}

^{3.Energy produced on             (c) sound energy burning of wood}

^{4. Vibrating membrane            (d) Muscular of a drum energy}

^{5. Energy of human                 (e) Potential energy beings}

^{4. Define these terms .                              (1×5=5)}

^{(a) Joule        (b) Energy.    (c) Magnetic energy   (d) Muscular energy  (e)  Conservation law of energy}

^{Section –B                                                (2×10=20)}

^{5. Answer the following questions.}

^{(a) State laws of reflection .}

^{(b) State any three uses of a plane mirror}

^{(C) The incidence angle for a light ray is 45 degree . Find the value of angle of reflection .}

^{(d) Briefly explain light energy .}

^{(e)  What  is solar energy ? What is its significance ?}

^{(f) Explain translatory motion .}

^{(g) What do you mean by multiple motion ? Give some examples too .}

^{(h) Define speed and give its SI unit .}

^{(I) The diameter of a coin is 4.2 cm . Find its surface area .}

^{(j) Find the area of a circle of radius 7 cm.}