Everyday Science

The Compact Disc (CD) was developed jointly by Sony and Philips in the late 1970s, with the first commercial CDs released in 1982. Both companies collaborated rather than developed the CD independently, but they are credited together for its invention.

Daniel Gabriel Fahrenheit invented the mercury-in-glass thermometer, which is considered the basis for the modern clinical thermometer, often called the Doctor's Thermometer. The other options are incorrect or misspelled.

Ampex was the first company to develop and market the video tape recorder in 1956, predating Mitsubishi's VHS system introduced in 1969. Therefore, Ampex is correctly identified as the maker of the first video recorder.

Robert Noyce co-invented the integrated circuit in 1959, which allowed electronic equipment to become much smaller and more efficient compared to earlier technologies like transistors and vacuum tubes. This invention was crucial in miniaturizing electronic devices.

A hygrometer is an instrument specifically designed to measure the relative humidity in the air. It does not measure distance, current, or any other parameter.

William Shockley, John Bardeen, and Walter Brattain invented the transistor at Bell Labs in 1947, which revolutionized the electronics industry by enabling smaller, more efficient electronic devices.

Saturn currently holds the record for the planet with the maximum number of moons, surpassing Jupiter. Recent discoveries have increased Saturn's known moons to over 80, making option B correct.

Electric current can produce chemical effects (electrolysis), magnetic effects (electromagnetism), and heating effects (Joule heating). Therefore, all the listed effects are produced by electric current.

A solar eclipse occurs when the Moon passes between the Earth and the Sun, blocking the Sun's light either partially or completely. This aligns with option C, which correctly describes the Moon's position during a solar eclipse.

Water reaches its maximum density at approximately 4°C due to the molecular arrangement of water molecules at this temperature, making option C correct.