Ques No.1: Nowadays, the international communication and transmission is being done through the waves known as ________.
Ques No.2: Gypsum is used for _______.
Ques No.3: In a telephone receiver, _______ is placed under the diaphragm.
Ques No.4: The major part of natural gas, petroleum and coal consist of ________.
Ques No.5: First telegraph signal was transmitted in ______.
Ques No.6: The only planet of solar system which has water vapours is _________.
Ques No.7: The waves used for sending signals to the satellite from ground station are _________.
Ans: Micro Waves
Ques No.8: Tincture of iodine consists of ________.
Ans: A solution of iodine in alcohol
Ques No.9: In a colour television, the colours are __________.
Ans: green, red and blue
Ques No.10: __________ are nitrogen-fixing micro-organisms which can enrich soil.
Ans: Bio fertilisers