Physics-
General
Easy
Question
The slit of a collimator is illuminated by a source as shown in the adjoining figures. The distance between the slit S and the collimating lens L is equal to the focal length of the lens. The correct direction of the emergent beam will be as shown in figure
- 1
- 3
- 2
- None of the figures
The correct answer is: 2
In case of convex lens if rays are coming from the focus, then the emergent rays after refraction are parallel to principal axis.
Related Questions to study
physics-
Two similar plano-convex lenses are combined together in three different ways as shown in the adjoining figure. The ratio of the focal lengths in three cases will be
Two similar plano-convex lenses are combined together in three different ways as shown in the adjoining figure. The ratio of the focal lengths in three cases will be
physics-General
physics-
White light is incident on the interface of glass and air as shown in the figure. If green light is just totally internally reflected then the emerging ray in air contains
White light is incident on the interface of glass and air as shown in the figure. If green light is just totally internally reflected then the emerging ray in air contains
physics-General
physics-
A ray of light is incident at an angle i from denser to rare medium. The reflected and the refracted rays are mutually perpendicular. The angle of reflection and the angle of refraction are respectively r and r’, then the critical angle will be
A ray of light is incident at an angle i from denser to rare medium. The reflected and the refracted rays are mutually perpendicular. The angle of reflection and the angle of refraction are respectively r and r’, then the critical angle will be
physics-General
physics-
A fish is a little away below the surface of a lake. If the critical angle is 
, then the fish could see things above the water surface within an angular range of 
where
A fish is a little away below the surface of a lake. If the critical angle is , then the fish could see things above the water surface within an angular range of where
physics-General
physics-
A ray of light passes through four transparent media with refractive indices 
as shown in the figure. The surfaces of all media are parallel. If the emergent ray CD is parallel to the incident ray AB, we must have
A ray of light passes through four transparent media with refractive indices as shown in the figure. The surfaces of all media are parallel. If the emergent ray CD is parallel to the incident ray AB, we must have
physics-General
chemistry-
The acidic character of 
alcohols, 
and 
is of the order
The acidic character of alcohols, and is of the order
chemistry-General
chemistry-
Ethanol is more soluble in water but ether is less soluble because:
Ethanol is more soluble in water but ether is less soluble because:
chemistry-General
chemistry-
How many structural isomers are known for 
How many structural isomers are known for
chemistry-General
chemistry-
Methanol and ethanol can be distinguished by the following:
Methanol and ethanol can be distinguished by the following:
chemistry-General
chemistry-
An alcohol on alk. 
oxidation gives first acetone and on further oxidation acetic acid. It is:
An alcohol on alk. oxidation gives first acetone and on further oxidation acetic acid. It is:
chemistry-General
chemistry-
The alcohol that produces turbidity immediately with 
at room temperature
The alcohol that produces turbidity immediately with at room temperature
chemistry-General
chemistry-
The conversion of m-nitrophenol to resorcinol involves respectively
The conversion of m-nitrophenol to resorcinol involves respectively
chemistry-General
chemistry-
At 530 K, glycerol reacts with oxalic acid to produce
At 530 K, glycerol reacts with oxalic acid to produce
chemistry-General
chemistry-
The following reaction is known as 
The following reaction is known as
chemistry-General
chemistry-
On heating glycerol with conc.
a compound is obtained which has bad odour. The compound is:
On heating glycerol with conc. a compound is obtained which has bad odour. The compound is:
chemistry-General
