CLASS: IX
SUBJECT: SCIENCE (086) Assignment No.: 1, 2023-24
PHYSICS
Q1. Choose the correct option from the following :
(i). A car is moving along a straight road with uniform velocity. It is shown in the graph
(ii). The numerical ratio of displacement to distance for a moving object is
(a) always less than 1 (b) always equal to 1
(c) always more than 1 (d) equal to or less than 1
(iii) If the velocity of a car increases from 15m/s to 20m/s in 10sec, then the acceleration produced in the car is
(a) 2m/s2 (b) 0.5m/s2 (c) -2m/s2 (d) -0.5m/s2
Q2. For the given questions (i), (ii) and (iii) , two statements are given- one labeled Assertion (A) and the
other labeled Reason (R).
Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below:
(a) Both A and R are true, and R is correct explanation of the assertion.
(b) Both A and R are true, but R is not the correct explanation of the assertion.
(c) A is true, but R is false.
(d) A is false, but R is true.
(i). Assertion: The distance-time graph of uniform motion is a straight line.
Reason : Dependent variable is along y-axis and independent variable is along x-axis.
(ii) Assertion: The velocity of a body is a scalar quantity.
Reason : A vector quantity has both magnitude and direction.
(iii) Assertion : A body can have acceleration even if its velocity is zero at a given instant.
Reason : A body is momentarily at rest when it reverses its direction of motion.
Q3. The distance-time graph of a body is shown in Fig. Find the speed of the body as it moves from :
(i) O to A (ii) A to B and (iii) B to C.
BIOLOGY
Q4. Choose the correct option.
(i) While examining a thin slice of cork, Robert Hooke saw that the cork resembled