CBSE VIII

CBSE VIII Science Set - 3

Question 1

When two forces act along the same direction on an object, then the net force acting on the object is ____ of the two forces.
A) the average
B) less than the sum
C) greater than the sum
D) equal to the sum

Question 2

When we rub our palms together vigorously, they become warm because muscular energy is converted into heat energy due to the friction between the palms.
A) True
B) False

Question 3

All animals including human beings communicate with sounds in the range of 20 Hz and 20,000 Hz.
A) True
B) False

Question 4

A student prepared a tester using a compass needle for testing the conductivity of liquid samples. He then made the following observations:
(i) The deflection of the compass needle with sample A is 5 units

(ii) The deflection of the compass needle with sample B is 3 units

(iii) The deflection of the compass needle with sample C is 8 units

(iv) The deflection of the compass needle with sample D is 10 units

The liquid sample with the highest conductivity is ____.

A) sample A
B) sample B
C) sample C
D) sample D

Question 5

The weak points on the earth's crust, where the earthquakes are likely to occur, are called tectonic plates.
A) True
B) False

Question 6

At the junction of the optic nerve and the retina, there are no sensory cells, so no vision is possible at that spot. This is called the ____ spot.
A) white
B) black
C) blind
D) dead

Question 7

Which of the following celestial bodies appears to change its position with respect to the stars?
A) The Earth
B) Constellations
C) The Milky way
D) Galaxies

Question 8

Which was the first synthetic fibre to be made entirely of chemicals?
A) Nylon
B) Polyester
C) Rayon
D) Terylene

Question 9

Special refined kerosene oil is used as a fuel in ____.
A) heavy vehicles
B) light vehicles
C) ships
D) aeroplanes

Question 10

Study of a nucleus is known as ____.
A) neurology
B) radiology
C) karyology
D) rhinology