PHYSICS

Why is echo not heard in our living rooms? To hear echo, the minimum distance between the source and the reflector must be 17m. When this distance is more than 17m, the reflected sound can be distinguished from the original. As the length of our rooms is less than 17m, we don't hear echo.

  SAMPLE PAPER FOR ICSE 2020 onwards, PHYSICS EXAM, 13 MARCH 2020  PHYSICS CLASS 10 FULL MARKS 80 GENERAL INSTRUCTIONS: 1. ANSWERS TO THIS QUESTION PAPER SHOULD BE WRITTEN IN ANSWER SHEETS PROVIDED SEPARATELY. 2. You ARE NOT ALLOWED TO WRITE IN FIRST 15 MINUTE. SPEND THIS TIME TO READ THE QUSETIONS THOROUGHLY. 3. THIS QUESTION PAPER IS DIVIDED INTO TWO SECTIONS: SECTIONS A AMD SECTION B. 4. SECTION A: ATTEMPT ALL QUESTIONS FROM THIS SECTION. 5. SECTION B : ATTEMPT ANY FOUR QUESTION. 6. MARKS ARE GIVEN IN BRACKETS [ ].  SECTION A (ATTEMPT ALL QUESTIONS )  QUESTION 1  a) Define centre of gravity and mark it for a triangular lamina. 2  b) A body of mass 500g is thrown vertically upwards with a velocity of 9.8 m/s, calculate the potential energy at the maximum height. (g=10m/s^2) 2 c) Name the class of lever for a short handle oar. Give one more example of this class of lever. 2  d) Screw Jack has a long handle bar. Give reason. 2 e) A...