## Saturday, June 18, 2011

### Science Class VIIth Test From Chapter 13 – Motion and Time

M.M: 43 marks                           Date: 18/06/2011 Time: 1 hour 15 minutes

Q 1: Write True or False for the give statements, also correct the false statements.  (1 mark per question x 10 = 10 marks)

i. In ancient times, measurement of time was done by watches –
ii. A day has 8,640 seconds –
iii. The body moving in a curved line is said to have curvilatory motion –
iv. The time taken for one oscillation is called time gap –
v. Time = (Speed) / (Distance) -
vi. The basic unit of speed is km./min. –
vii. The time period of a pendulum is constant –
viii. The symbols of all the units of distance and time etc. is written in plural –
ix. By only knowing the distance covered by two bodies, it can be found which is faster –
x. If the distance-time graph of an object is a horizontal line parallel to the time axis, then the object is moving at constant speed -

Q 2: Fill in the blanks (1 mark per question x 13 = 13 marks, more than one word may come at certain blanks).

i. The point of intersection of ____________ and ___________ is called origin.
ii. The __________ of an object can be obtained from the distance-time graph.
iii. A __________ ________ is a diagram which shows the percentage composition of something in the form of slices of a circle.
iv. A ________ measures time by the position of the shadow cast by the Sun.
v. Sand clock is also known as _________________.
vi. 10 ___________ = 1 century.
vii. 10 centuries = 1 _____________
viii. Clocks are based on the principle of ______________ motion.
ix. The time-period of a pendulum depends on its _____________.
x. One complete to-and-fro movement of the pendulum bob is called an _____________.
xi. The maximum displacement of the bob form its mean position on either side is called the _____________ of pendulum.
xii. The quartz clocks and watches can be two types: _____________ and __________________.
xiii. The smallest time interval that can be measured with commonly available clocks and watches is ________________.

Q 3: Which of the two is a bigger unit of time: microsecond or nanosecond?                     (1 mark)

Q 4: What is the smallest time interval which can be measured accurately with clocks and watches used in Sports Meets?                                (1 mark)

Q 5: A pendulum takes 270 seconds for 18 complete oscillations. What is the time-period of this pendulum?                                         (2 marks)

Q 6: Calculate the number of seconds in one year.          (2 marks)

Q 7: The given figure shows the distance time graph for the motion of two vehicles A and B. Which one of them has faster speed?       (2 marks)
 Distance Time graph

Q 8: Out of a line graph, a pie chart and a bar graph, which one will be suitable for the given cases:                                            (3 marks)

i. Runs scored in various over of a cricket match.
ii. Percentage composition of air
iii. Distance covered by a truck with time.

Q 9: A bus starts from rest at 9 AM. The distances covered by the bus at various instants of time are given below.                                             (3 marks)

 Distance (km) 0 25 50 75 100 Time (AM) 9 09:30 10:00 10:30 11:00

i. Draw the distance-time graph for the bus.
ii. What was the distance covered by the bus at 10:45 AM?

Q 10: A sprinter attains a maximum speed of 12 m/sec. Calculate his speed in:                  (2 marks)

i. km/hr
ii. mm/sec

Q 11: What is meant by uniform and non uniform motion? Give an example of each.           (2 marks)

Q 12: A car moves with a speed of 50 km/hr for 15 minutes and then with a speed of 70 km/hour for the next 15 minutes. Find the total distance covered by the car.                                   (2 marks)

#### 1 comment:

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