Q:- What are Spherical mirrors? Explain, how a concave mirror is different from a convex mirror?
Q:- Explain the laws of refraction of light.
Q:- What do you understand by Resistance in Series?
Q:- what is meant by potential difference? How is it measured ?
Q:- Discuss the working of Human Eye as a system of refraction of light.
Q:- Explain the phenomenon of Dispersion of light by a Glass prism .
Q:- what is Oersted Experiment ? What is effect of a Bar magnet on a compass needle ?
Q :- what is an Electric Motor ? Give its principle.
Q:- Define Nuclear Energy.
Q:- a convex lens is of focal length 2 meters. What is the power of lens?
Q:- what is the use of Rear view mirror in vehicle?
Answers
Q:- What are Spherical mirrors? Explain, how a concave mirror is different from a convex mirror?
Spherical mirrors are the part of glass sphere whose inner or outer side is polished and non-reflecting. Most of the curved mirror is a spherical mirror. If the reflecting surface of a spherical mirror is concave,it is called a concave mirror. If the reflecting surface is convex,then it is a convex mirror.
Answer:
1) Spherical mirrors are those who's reflecting surface is appear to be the part of Sphere.
*Concave mirror :- Mirror whose reflecting surface is curved inwards.
*Convex mirror :- Mirror whose reflecting surface is curved outwards.
2) LAWS OF REFRACTION:-
(i) Ist law:- Incident ray, refracted ray and normal to the interface of two transparent media at the point of incidence , all they lie in the same plane.
(ii) IInd law:- The ratio of Sin of angle of incidence to the Sin of angle of refraction is a constant.
Sin i / Sin r = Constant.
3) When resistors are connected end to end, they are said to be "Resistors in Series connection".
4) Work done in bringing unit positive charges from one point to another point in electrical field is called Potential Difference (V).
V = W/Q .
The Potential Difference is measured through the device called "Voltmeter".
5) Light rays from an object refract by lens to form real and inverted image on Retina. The Retina cells are stimulated by light and converts stimulation into corresponding electric signal, which is carried by optic nerve to Brain where analysis takes place.
6) When white light is passed through Prism, it splits into constituent colours namely Violet, Indigo, Blue, Green, Yellow, Orange and Red. This phenomenon is called Dispersion.
7) OERSTED EXPERIMENT:-
When current carrying conductor is kept about the magnetic needle it shows deflection. When direction of current is reversed, the magnetic needle also deflects in opposite direction. This indicates that current carrying conductor produces magnetic field around it.
Deflection takes place when Bar magnet is placed on a compass needle.
8) Electric Motor is a device, which converts electrical energy into mechanical energy.
Principle of Electric Motor :- Current carrying conductor placed in magnetic field experience mechanical force.
9) Energy which obtained from the nucleus is called "Nuclear Energy".
10)
Given,
Lens = Convex lens,
Focal length = 2 meters.
Power of lens (P)= ?
Power of lens is defined as the reciprocal of its focal length. So,
P = 1/f.
P = 1/2.
P = +0.5 D.
Here, D means Dioptre, which is the the S.I unit of Power of lens.
11) Convex mirror is used as a rear view mirror. It gives a virtual effect and diminished image of the object in front of it. They (Convex mirror) are preferred as rear view mirror in vehicle. Because, they give a wider field of which allows the driver to see most of the traffic behind him.