Which one among the following is the primary reason for asking persons undergoing X-ray imaging to remove metallic objects?
Metallic objects can absorb/reflect X-ray resulting in dark/bright spot
Metallic objects can absorb or reflect X-rays differently from body tissue, which shows up as unwanted dark or bright spots (artifacts) on the resulting X-ray image and can obscure the area being examined. This is the primary reason patients are asked to remove jewellery, belts, and other metallic items before undergoing X-ray imaging.
An echo is heard after 5 seconds of the production of sound which moves with a speed of 340 m/s. What is the distance of the mountain from the source of sound which produced the echo?
Which of the following lenses will bend the light rays through the largest angle?
Which one of the following statements with regard to ultra violet light is NOT correct?
A sound wave has a frequency of 4 kHz and wavelength 30 cm. How long will it take to travel 2.4 km ?
A photon of X-ray has energy of 1 keV. A photon of visible radiation has energy of 3 eV. In this context, which one of the following statements is not correct?
Which one of the following statements is not correct?
Which one of the following statements is not correct?
A person rings a metallic bell near a strong concrete wall. He hears the echo after 0.3 s. If the sound moves with a speed of 340 m/s, how far is the wall from him?
Sonic boom is produced when a source of sound travels at a speed:
If the wavelengths corresponding to ultraviolet, visible and infrared radiations are given as λ UV ,λ VIS and λ IR respectively, then which one of the following gives the correct relationship among these wavelengths?
Which of the following is correct?
I. Sound is a mechanical wave
II. Sound wave does not need any medium to propagate
At a particular temperature, sound propagates in ______ at the fastest speed .
The atmospheric green house effect is produced mainly by the absorption and re-emission of:
Which of the following are examples of electromagnetic waves?
a. Television waves
b. Ultraviolet rays
c. X-rays
d. Sun rays
Sound waves having frequency less than 20 Hz are called ________ waves.