Verify laws of Reflection using Plain Mirror Experiments with video presentation for std 10

1.  TO VERIFY THE LAWS OF REFLECTION USING A PLANE MIRROR

Aim : To verify the laws of reflection using a plane mirror.
Principle : When a ray of light is incident on a reflecting surface, it changes its direction of motion and travels in the original medium following certain laws. This phenomenon is called reflection of light.
Apparatus : Drawing board, a drawing paper (White), a plane mirror, a foot-rule, a pencil, four pins, four push pins, a protactor, a stand for the plane mirror.

Ø First of all fix the white drawing paper on the drawing board using push pins.

Pins up Paper on Wooden board

Ø First of all fix the white drawing paper on the drawing board using push pins. Place the plane mirror along with its stand and fix its position AB.

Verify Laws of Reflection using plain Mirror

Ø Now draw a line PQ which passes through the mid-point ‘P’ of AB and perpendicular to AB.

Ø PQ is called the normal to AB.

Law of Reflection Of Plain Mirror

Ø Draw a ray RP which makes some angle with the normal (PQ).

Ø Draw a ray RP which makes some angle with the normal (PQ). On the ray RP fix two pins P₁ and P₂ vertically with 2-3 cm separation between them. Ray RP is incident ray.

Reflection using Plain Mirror

Ø Now from the other side of PQ , (in which incident ray is not there) see the images of pins P₁ and P₂ fix other two pins P₃ and P₄ vertically so that pins P₃, P₄ and images P₁ and P₂ appears collinear at their lower ends.

To Verify Laws of Reflection using Plain Mirror

Ø Now remove the pins and the mirror. Join the marks of P₃ andP₄ and obtain the reflected ray PS.

Reflection by a Plain Mirror

Ø Repeat  the experiment for different angles of incidence. Measure angle of incidence and angle of reflection. Note your reading in the observations table.

Observation of Reflection of Plain Mirror

Conclusion :

Practical Uses:

We can study the laws of reflection. We can also study the images obtained by the plane mirror. We can come to know how reflection is used in various optical appliances, e.g., periscope, keleidoscope.

Video :

To Verify the Laws of Reflection using Plain Mirror

Angle of Prism, Physics practical for the standard 12

REFRACTIVE INDEX OF PRISM

AIM:-

Determine with the help of pins, the angle of the given glass prism. Determine the values of angle of emergence and angle of deviation for four different values of angle of incidence. Hence prove that i + e = A +d.

PRINCIPLE :

Reflection and refraction of light.

PRECAUTIONS
 While marking the position of a prism with pencil, the prism should not be disturbed. 
A prism should be carefully put back exactly at the marked position. 
While pressing the heads of the pins for fixing them use metal coin or a hard object so that you do not hurt your palm. 
Do not press the pins very hard in the board otherwise it becomes difficult to remove them afterwards. 
See that the pins pushed in the board remain perpendicular to the board.

Angle of Prism 

Angle of Prism Conclusion

REFRACTIVE INDEX OF PRISM

AIM :-

Using pins with a given prism determine the angles of deviation for six different values of angle of incidence. Draw the graph of angle of deviation versus angle of incidence. Determine, from this the angle of minimum deviation and using following formula determine refractive index of material of the prism.

Angle of Prism Formula

Angle of prism, A = ……. .

Angle of Deviation measure

Angle of Deviation

Angle of Deviation Observation table  

Angle of Deviation Graph