Stars which appears single to the naked eye but are double stars when observed by a telescope, are known as _____.

1. 1. Quasars
   2. Novae and supernovae
   3. Cosmic Stars
   4. Binderies 

How many of the eight planets of the solar system were known in the life time of Kepler, the formulator of laws of planetary motions?

1. 1. 6
   2. 7
   3. 8
   4. All the planets

How many days does the moon take to return to the same position among the constellations?

1. 1. 20 days
   2. 23 days
   3. 26 days
   4. 28 days

Some times the moon passes between the sun and the earth this phenomenon is known as _____.

1. 1. Earth eclipse
   2. Solar eclipse
   3. Lunar eclipse
   4. None of these

A Comet _____.

1. 1. Has a tail always pointing towards the sun
   2. Has a tail, sometimes pointing towards the sun and sometimes away from it
   3. has no tail at all
   4. Has a tail always pointing away from the sun

The comet, named after Edmund Halley, reappears after a time interval of every _____.

1. 1. 40 years
   2. 76 years
   3. 116 years
   4. 120 years

How long does a sun-ray take to travel form the sun t the earth?

1. 1. 300 sec
   2. 450 sec
   3. 498 sec
   4. 500 sec

Who was the first to determine that the day on the Mars was, like ours, roughly twenty-four hours long?

1. 1. Giordano Bruno
   2. Christians Huygens
   3. Copernicus
   4. Isaac Newton

Computer is _____.

1. 1. a device to correct the mental balance of mad persons
   2. an instrument to measure electronic quantities
   3. an instrument to measure electrical quantities
   4. a device designed to find instant solutions of huge and complex calculations based on the information already fed

Rectifier is used for _____.

1. 1. changing D.C. into A.C.
   2. changing A.C. into D.C.
   3. increasing the voltage in line
   4. None of the above