Speed of sound

Why sound travels faster in humid air than normal air as humid air is denser than normal air? (Akash asked) Answer: The speed of sound in a medium is inversely proportional to the square root of its density. Humid air is less dense than dry air. Therefore the speed of sounf in humid air is greater than that in … Continue reading Speed of sound

What is Eddy Current?

Eddy currents are circulating currents induced in the body of a solid conductor whenever the magnetic flux linked with it changes. It is called EDDY CURRENT because they are like eddies formed in water. http://youtu.be/zJ23gmS3KHY Also read http://askphysics.com/ask-physics/eddy-currents-applications/

CBSE 12th Std Physics Numerical from Optics

A convex lens of crown glass(1.5) has a focal length of 15 cm. The lens is placed in (a) water(1.33) and carbon bisulphide(1,65).determine in each case whether the lens behaves as a conveging or a diverging lens and determine its focal length. (Asked by Shobha) Answer: Formula used For the lens to be converging, f … Continue reading CBSE 12th Std Physics Numerical from Optics

Problem from relative velocity

A Boat covers certain distance between two spots in a river taking t1 hrs going downstream and t2 hrs going upstream. What time will be taken by boat to cover same distance in still water? posted by STUTI Answer: Incoming search terms:relative velocity...

Where is electricity stored after it is generated but before it is supplied? (Chat Transcript from FaceBook)

Where is electricity stored after it is generated but before it is supplied? Mahesh Sable Electrical power cannot be stored and,therefore,power plants must produce power as and when demanded.power stations r connected in parallel hence load is equally distributed,electric Power can be adjusted with help of step up or step down transformers.   Mathew Abraham … Continue reading Where is electricity stored after it is generated but before it is supplied? (Chat Transcript from FaceBook)

Dimensions and conversion of units

The height of mercury column in a barometer in a Calcutta laboratory was recorded to be 75 cm. Calculate this pressure in SI and CGS units using the following data : specific gravity is 13.6, density of water is 1000 kg/m3, g is 9.8 m/s2 at Calcutta. Pressure = hρg in usual symbols Your email: 

PhysicsWorld reports: Flowing water may exist on Mars!

Images from NASA’s Mars Reconnaissance Orbiter (MRO) reveal that dark, narrow, finger-like structures follow slopes in certain regions of the southern hemisphere of the planet during its summer months. The researchers believe that these could be caused by flowing salt water and say the finding raises the tantalizing prospect that there might be life on Mars. [...]