Characteristics of ideal fuel: It should be readily available. It should be economical. It should burn easily in air at a moderate rate. It should produce a large amount of heat. It should have high calorific value. It should not leave behind any undesirable substances on combustion. The fuel shouldRead more
Characteristics of ideal fuel:
It should be readily available.
It should be economical.
It should burn easily in air at a moderate rate.
It should produce a large amount of heat.
It should have high calorific value.
It should not leave behind any undesirable substances on combustion.
Good source of energy should have the following characteristics: It should do a large amount of work per unit mass or volume – it means that the output energy must be more than the input energy. It should have high calorific value. It should be easily accessible – the energy source should be able toRead more
Good source of energy should have the following characteristics:
It should do a large amount of work per unit mass or volume – it means that the output energy must be more than the input energy. It should have high calorific value.
It should be easily accessible – the energy source should be able to provide energy over a long period of time. Example: coal and petroleum.
Should be easy to store and transport – most common sources of energy such as coal, petrol, and LPG need to be transported to users from their points of production. They also need proper storage. Thus, it is important to store and transport these sources safely and economically.
Should be safe and convenient to use – energy sources should be safe as it is used by a large number of people and should be convenient. Example: Nuclear energy from a nuclear power plant is hazardous to be used at homes.
A student has difficulty in reading the blackboard while sitting in the last row. It shows that he is unable to see distant objects clearly. He is suffering from myopia. This defect can be corrected by using a concave lens.
A student has difficulty in reading the blackboard while sitting in the last row. It shows that he is unable to see distant objects clearly. He is suffering from myopia. This defect can be corrected by using a concave lens.
The near point of the adult human eye is 25 cm from which the object can be seen clearly without any strain over the eyes. Whereas the far point of the eye is infinity.
The near point of the adult human eye is 25cm from which the object can be seen clearly without any strain over the eyes.
Drivers use convex mirror as a rear-view mirror in automobiles because of the following two reasons: 1. A convex mirror always forms an erect, virtual and diminished image of an object placed anywhere in front of it. 2. A convex mirror has a wider field of view than a plane mirror of the same size.Read more
Drivers use convex mirror as a rear-view mirror in automobiles because of the following two reasons:
1. A convex mirror always forms an erect, virtual and diminished image of an object placed anywhere in front of it.
2. A convex mirror has a wider field of view than a plane mirror of the same size.
Thus convex mirrors enable the driver to view much larger traffic behind him than would be possible with a plane mirror. The main disadvantage of a convex mirror is that it does not give the correct distance and the speed of the vehicle approaching from behind.
When light rays parallel to the principal axis coming from infinity fall on the surface of the concave mirror, it converges at a single point on the principal axis. This point is called ‘Principal Focus of concave mirrors. The principal focus is also referred to as simply focus or focal point. The cRead more
When light rays parallel to the principal axis coming from infinity fall on the surface of the concave mirror, it converges at a single point on the principal axis. This point is called ‘Principal Focus of concave mirrors. The principal focus is also referred to as simply focus or focal point. The concave mirror focal point lies in front of the mirror.
What is a good fuel?
Characteristics of ideal fuel: It should be readily available. It should be economical. It should burn easily in air at a moderate rate. It should produce a large amount of heat. It should have high calorific value. It should not leave behind any undesirable substances on combustion. The fuel shouldRead more
Characteristics of ideal fuel:
- The fuel should have proper ignition temperature.
See lessWhat is a good source of energy?
Good source of energy should have the following characteristics: It should do a large amount of work per unit mass or volume – it means that the output energy must be more than the input energy. It should have high calorific value. It should be easily accessible – the energy source should be able toRead more
Good source of energy should have the following characteristics:
- It should be eco-friendly.
See lessA student has difficulty reading the blackboard while sitting in the last row. What could be the defect the child is suffering from? How can it be corrected?
A student has difficulty in reading the blackboard while sitting in the last row. It shows that he is unable to see distant objects clearly. He is suffering from myopia. This defect can be corrected by using a concave lens.
A student has difficulty in reading the blackboard while sitting in the last row. It shows that he is unable to see distant objects clearly. He is suffering from myopia. This defect can be corrected by using a concave lens.
See lessWhat is the far point and near point of the human eye with normal vision?
The near point of the adult human eye is 25 cm from which the object can be seen clearly without any strain over the eyes. Whereas the far point of the eye is infinity.
The near point of the adult human eye is 25 cm from which the object can be seen clearly without any strain over the eyes.
Whereas the far point of the eye is infinity.
See lessA person with a myopic eye cannot see objects beyond 1.2 m distinctly. What should be the type of the corrective lens used to restore proper vision?
A person with a myopic eye can use concave lens to restore proper vision.
A person with a myopic eye can use concave lens to restore proper vision.
See lessWhat is meant by power of accommodation of the eye?
Accommodation is the process by which the vertebrate eye changes optical power to maintain a clear image or focus on an object as its distance varies.
Accommodation is the process by which the vertebrate eye changes optical power to maintain a clear image or focus on an object as its distance varies.
See lessWhy do we prefer a convex mirror as a rear-view mirror in vehicles?
Drivers use convex mirror as a rear-view mirror in automobiles because of the following two reasons: 1. A convex mirror always forms an erect, virtual and diminished image of an object placed anywhere in front of it. 2. A convex mirror has a wider field of view than a plane mirror of the same size.Read more
Drivers use convex mirror as a rear-view mirror in automobiles because of the following two reasons:
1. A convex mirror always forms an erect, virtual and diminished image of an object placed anywhere in front of it.
2. A convex mirror has a wider field of view than a plane mirror of the same size.
Thus convex mirrors enable the driver to view much larger traffic behind him than would be possible with a plane mirror. The main disadvantage of a convex mirror is that it does not give the correct distance and the speed of the vehicle approaching from behind.
See lessName a mirror that can give an erect and enlarged image of an object.
Concave mirror forms an erect, virtual and enlarged image when the object is between focus and pole of mirror.
Concave mirror forms an erect, virtual and enlarged image when the object is between focus and pole of mirror.
See lessThe radius of curvature of a spherical mirror is 20 cm. What is its focal length?
Radius of curvature, R = 20 cm R = 2f f = R/2 = 20/2 = 10 cm The focal length is 10 cm.
Radius of curvature, R = 20 cm
R = 2f
f = R/2 = 20/2 = 10 cm
The focal length is 10 cm.
See lessDefine the principal focus of a concave mirror.
When light rays parallel to the principal axis coming from infinity fall on the surface of the concave mirror, it converges at a single point on the principal axis. This point is called ‘Principal Focus of concave mirrors. The principal focus is also referred to as simply focus or focal point. The cRead more
When light rays parallel to the principal axis coming from infinity fall on the surface of the concave mirror, it converges at a single point on the principal axis. This point is called ‘Principal Focus of concave mirrors. The principal focus is also referred to as simply focus or focal point. The concave mirror focal point lies in front of the mirror.
See less