Question 1 :
When a glass rod is rubbed with a piece of silk cloth the rod ________________.
Question 3 :
The power of an earthquake is expressed in terms of a magnitude on a scale called
Question 4 :
The outermost layer of the earth is not in one piece. It is fragmented. Each fragment is called :
Question 6 :
The seismic waves are recorded by an instrument called the _________
Question 8 :
State true or false. Tremors on the earth can also be caused by the eruption of a volcano.
Question 11 :
Which part of the eye gets affected if someone is suffering from cataract?
Question 12 :
What is the angle of incidence of a ray if the reflected ray is at an angle of $90^{\circ}$ to the incident ray?
Question 13 :
When angle of incidence is equal to the angle of reflection
Question 14 :
The retina contains several nerve cells. Sensations felt by the nerve cells are then transmitted to the brain through the optic nerve. Is it TRUE OR FALSE?
Question 16 :
Fill in the blanks: A person 1 m in front of a plane mirror seems to be _____ away from his image?
Question 17 :
An image formed by a mirror the left of the object appears on the right and the right appears on the left. This is known as _______________ ?
Question 18 :
After striking the mirror, the ray of light is reflected in another direction. The light ray, which strikes any surface, is called ________ ?
Question 19 :
The angle between incident ray and reflected ray is $60^\circ$. What is the value of angle of incidence?
Question 20 :
What is the most comfortable distance at which one can read with a normal eye?
Question 21 :
At night, when the sky is clear and the moon is not there, sometimes bright streaks of light in the sky can be seen. These are commonly known as_______, although they are not stars. They are called _____
Question 23 :
True or false. Almost all festivals in India are celebrated according to the phases of moon.
Question 24 :
State true or false. The planet Venus appears in the eastern sky before sunrise.
Question 25 :
The moon completes one rotation on its axis as it completes one ________around the Earth.
Question 26 :
_______ is another prominent constellation in the northern sky. It is visible during winter in the early part of the night
Question 27 :
True or False. Saturn is the least dense among all the planets. Its density is less than that of water.
Question 29 :
The length of the the comet's tail grows in size as it approaches the _____.
Question 30 :
After full moon day, every night the size of the bright part of the moon appears to become ______ and _________