''When parallel sunrays are incident on concave mirror it converges...meet at focus and hence the solar cooker works'', but sun rays are not parallel at all so how can we say this??
''When parallel sunrays are incident on concave mirror it converges...meet at focus and hence the solar cooker works'', but sun rays are not parallel at all so how can we say this??
Dear student , first understand the concept that ,why we are saying sun rays are incidents parallely on the reflector ,
It because we know that sun rays are coming from far away , so from such a large distance traveling light rays are assumed to be parallel . There's no meaning that all the rays are parallel traveling , it's just an assumption .
Now to understand the actual way of working of solar cooker given below,
Generally concave mirror using as a reflector in solar cooker, another name for a concave mirror is a converging mirror, which pretty much sums up their purpose: point all the light that hits them on a singe point (the bit where all they rays actually cross each other is called the focal point). At this point, all the Infra Red radiation that has hit them (and been reflected by the mirror's surface) is focussed, and it is this IR radiation that actually does the heating up. Thus, the idea of a solar cooker is to put some food right on top of this focal point to greatly increase the amount of energy that is hitting it, and so heat it up and cook it.
Basically, they transfer all the energy that is hitting the large surface of the mirror to a very small spot.
It because we know that sun rays are coming from far away , so from such a large distance traveling light rays are assumed to be parallel . There's no meaning that all the rays are parallel traveling , it's just an assumption .
Now to understand the actual way of working of solar cooker given below,
Generally concave mirror using as a reflector in solar cooker, another name for a concave mirror is a converging mirror, which pretty much sums up their purpose: point all the light that hits them on a singe point (the bit where all they rays actually cross each other is called the focal point). At this point, all the Infra Red radiation that has hit them (and been reflected by the mirror's surface) is focussed, and it is this IR radiation that actually does the heating up. Thus, the idea of a solar cooker is to put some food right on top of this focal point to greatly increase the amount of energy that is hitting it, and so heat it up and cook it.
Basically, they transfer all the energy that is hitting the large surface of the mirror to a very small spot.
