1511. An electric current can produce :

A. Chemical effect
B. Heating effect
C. Magnetic effect
D. All of the above *

1512. The unit of home electricity energy consumption is :

A. Watt hour
B. Kilowatt hour *
C. Joule hour
D. None of these

1513. If the magnet is allowed to move freely, it will always point in the same direction, which is toward the north and south poles, for the following reasons:

A. Gravitational field
B. A lot of meta deposits on north and south poles
C. As a result of the north pole’s attraction and the western pole’s repulsion
D. Earth is huge magnet *

1514. When sound is reflected from floor,ceiling or a wall, it mixes with the original sound and changes its complexation, it is called as :

A. Sound
B. Echo
C. Reverberation *
D. Noise

1515. The speed of sound in dry air at 20 degree Celsius is about :

A. 130 meters per second
B. 230 meters per second
C. 330 meters per second *
D. 430 meteres per second

1516. The speed of light in vacuum:

A. 300 Million meters per second *
B. 300 million meters per hour
C. 300 million Kilometers per second
D. 300 Million kilometers per hour

1517. The time, light takes from the sun to reach earth is :

A. 8 Minutes *
B. 25 Minutes
C. 45 Minutes
D. 48 Minutes

1518. Light from the sun travels a distance before it reaches the earth :

A. 50 Million Kilometer
B. 100 Million Kilometer
C. 150 Million Kilometer *
D. 200 Million Kilometer

1519. The most suitable thermometer for measuring the boiling point of water is :

A. Mercury thermometer *
B. Alcohol thermometer
C. Bimetallic thermometer
D. Liquid crystal thermometer

1520. The density of water is greatest at :

A. -30 degree Centigrade
B. 0 degree centigrade
C. 4 degree centigrade *
D. 100 degree centigrade