A bulb is hanging over a table. At which portion of the table is the illuminance maximum '? If a plane mirror is placed above the bulb facing the table, will the illuminance on the table increase ?

An electric bulb is hanging over a table at a height of 1 m above it. The illuminance on the table directly below the bulb is 40 lux. The illuminance at a point on the table 1 m away from the first point will be about

Figure shows a small diffused plane source S placed over a horizontal table-top at a distance of 2.4 m with its plane parallel to the table-top. The illuminance at the point A directly below the source is 25 lux. Find the illuminance at a point B of the table at a distance of 1.8 m from A.

A point source emitting light uniformly in all directions is placed 60 cm above a table-top. The illuminance at a point on the table-top, directly below the source, is 15 lux. Find the illuminance at a point on the table-top 80 cm away from the first point.

Explain why hydrogen is not placed with the halogen in the periodic table.

In a compound statement which is made of 4 single statement then the number rows in the truth table is

A point source of light moves in a straight line parallel to a plane table. Consider a small portion of the table directly below the line of movement of the source. The illuminance at this portion varies with its distance r from the source as

A uniform chain of mass m and length l overhangs a table with its two third part on the table. Fine the work to be done by a person to put the hanging part back on the table.