How much light does the umbra region of a shadow receive from the source?

How does the nature of a shadow depend on the light source?

What is the region of a shadow that receives some light from the source and gets partially illuminate called?

A source of sound of frequency 300 Hz and a receiver are located along the same line normal to the wall as shown in the figure. Both the source and the receiver are stationary and the wall receeds from the source with velocity 20ms^-1 .If the beat frequency registered by the receiver is 240/x Hz then x is : (Assume V_("sound")=300 m/s).

A point source of light is placed at a depth of h below the surface of water of refractive index mu . A floating opaque disc is placed on the surface of water so that light from the source is not visible from the surface. The minimum diameter of the disc is

How much time does the bob of a second.s pendulum take to move from one extreme to the other extreme of its oscillation?

A source of light is at 10 cm from a convex mirror and is then moved to a distance of 2 cm from the mirror. How much does the image move if the radius of curvature of the mirror is 4.8 cm?

Four brothers splitting a sum of money between them. The first brother receives 50% of the total, the second receive 25% of the total, the third receives 20% of the total, and the fourth receives the remaining $4 . How much more does the first brother receive than the third brother?

How much energy does 1 gm of fat yields?

Find out the source of water in your region/locality. Is water from this source available to all people living in that area?

A source of sonic oscillations with frequency n=1700Hz and a receiver are located on the same normal to a wall. Both the source and receiver are stationary, and the wall recedes from the source with velocity u=6.0(m)/(s) . Find the beat frequency registered by the receiver. The velocity of sound is v=340(m)/(s) .