Physics - Study Mode

[#696] The scientist who first sent electromagnetic waves to distant places is
Correct Answer

(C) Thomas Alva Edison

Explanation

Solution: Radio is the transmission of signals through free space by electromagnetic radiation of a frequency significantly below that of visible light, in the radio frequency range, from about 30 kHz to 300 GHz. These waves are called radio waves. Experiments were undertaken by Thomas Edison and his employees of Menlo Park. Edison applied in 1885 to the U.S. Patent Office for a patent on an electrostatic coupling system between elevated terminals. The patent was granted as U.S. Patent 465,971 on December 29, 1891. The Marconi Company would later purchase rights to the Edison patent to protect them legally from lawsuits.

[#697] The wave theory of light can explain
Correct Answer

(D) Interference of light

Explanation

Solution: The wave theory of light can explain interference of light.

[#698] Quality of transmission depends upon
Correct Answer

(C) Both (A) and (B)

Explanation

Solution: Quality of transmission is governed both by nature of signal and nature of communication channel/medium.

[#699] Circuit breaker usually operate under
Correct Answer

(B) Transient state of short-circuit current

Explanation

Solution: Circuit breaker usually operate under transient state of short-circuit current.

[#700] The resistance of the human body (dry condition) is of the order of
Correct Answer

(D) None of these

Explanation

Solution: According to National Institute of occupational safety and health, Under dry condition, the resistance of the human body is 100,000 ohms. Under wet condition, the resistance is reduced to 1000 ohms.