To see on object placed at a distance of less than 25cm, the ciliary muscles have to make the focal length still smaller, which puts strain on the ciliary muscles and they cannot make the focal length so small. Hence it is not possible to see at distance lens then 25 cm.
To see on object placed at a distance of less than 25cm, the ciliary muscles have to make the focal length still smaller, which puts strain on the ciliary muscles and they cannot make the focal length so small. Hence it is not possible to see at distance lens then 25 cm.
Current is flowing clockwise through a circular loop. The direction of magnetic field around the conductor can be known by using the right hand thumb rule. As the figure shows, the magnetic field would be towards the plane of the paper when it is inside the loop. On the other hand, the magnetic fielRead more
Current is flowing clockwise through a circular loop. The direction of magnetic field around the conductor can be known by using the right hand thumb rule. As the figure shows, the magnetic field would be towards the plane of the paper when it is inside the loop. On the other hand, the magnetic field would be away from the paper when it is outside the loop.
If the field lines would cross each other then the direction of field line would change at the point of crossing which is practically impossible. Hence, two magnetic field lines never intersect each other.
If the field lines would cross each other then the direction of field line would change at the point of crossing which is practically impossible. Hence, two magnetic field lines never intersect each other.
Properties of magnetic field lines: (a) Magnetic field lines follow the direction from the north pole to the south pole. (b) Magnetic field lines always show concentric pattern. (c) Magnetic field lines do not cross one another. (d) Closer the field lines; stronger is the magnetic field and vice-verRead more
Properties of magnetic field lines:
(a) Magnetic field lines follow the direction from the north pole to the south pole.
(b) Magnetic field lines always show concentric pattern.
(c) Magnetic field lines do not cross one another.
(d) Closer the field lines; stronger is the magnetic field and vice-versa is also true.
(e) Magnetic field lines are closer near the poles; which shows greater strength of magnetic field near the poles.
When a compass needle is brought near a bar magnet, the compass needle experiences a deflection. This happens because of interaction of magnetic fields of the compass needle and the bar magnet.
When a compass needle is brought near a bar magnet, the compass needle experiences a deflection. This happens because of interaction of magnetic fields of the compass needle and the bar magnet.
Environmental consequences of increasing demand for energy are as follows: 1.Use of fossil fuels is increasing air pollution which is not good for our health. 2. Air pollution is causing much damage to the ecosystem. 3. Greenhouse effect has resulted in global warming which is manifesting itself inRead more
Environmental consequences of increasing demand for energy are as follows:
1.Use of fossil fuels is increasing air pollution which is not good for our health.
2. Air pollution is causing much damage to the ecosystem.
3. Greenhouse effect has resulted in global warming which is manifesting itself in strange changes in the weather pattern around the world.
4. Too much exploitation of fossil fuels is going to create a situation when there would be not fossil fuel.
Steps to reduce energy consumption:
1. Judicious use of energy is the only way.
2. Use public transport instead of private modes of transport.
3. Use bicycle whenever possible.
4. Walk for short distance commute.
5. Avoid unnecessary use of modern gadgets which consume lot of energy.
Advantages of Solar Cooker: - They are environment friendly. - Use of a solar cooker does not involve recurring expenses on fuel. Disadvantages of Solar Cooker: - Solar cooker is very slow. - Solar cooker can work only during summer months and is useless during winters and on cloudy days. - Solar coRead more
Advantages of Solar Cooker:
– They are environment friendly.
– Use of a solar cooker does not involve recurring expenses on fuel.
Disadvantages of Solar Cooker:
– Solar cooker is very slow.
– Solar cooker can work only during summer months and is useless during winters and on cloudy days.
– Solar cooker can be useful at those places which receive plenty of sunshine. This is useless in colder climates.
Why is a normal eye not able to see clearly the objects placed closer than 25 cm?
To see on object placed at a distance of less than 25cm, the ciliary muscles have to make the focal length still smaller, which puts strain on the ciliary muscles and they cannot make the focal length so small. Hence it is not possible to see at distance lens then 25 cm.
To see on object placed at a distance of less than 25cm, the ciliary muscles have to make the focal length still smaller, which puts strain on the ciliary muscles and they cannot make the focal length so small. Hence it is not possible to see at distance lens then 25 cm.
See lessThe far point of a myopic person is 80 cm in front of the eye. What is the nature and power of the lens required to correct the problem?
Concave lens P=1/f=−100/80=−1.25D
Concave lens P=1/f=−100/80=−1.25D
See lessA person needs a lens of power –5.5 dioptres for correcting his distant vision. For correcting his near vision he needs a lens of power +1.5 dioptre. What is the focal length of the lens required for correcting
(i) f=1/P=−1/5.5=−0.1818m. f=−18.18cm. (ii) f=1/P=1/1.5=0.666m. f = 66.6cm.
(i) f=1/P=−1/5.5=−0.1818m.
f=−18.18cm.
(ii) f=1/P=1/1.5=0.666m.
See lessf = 66.6cm.
What is meant by power of accommodation of the eye?
The power of the eye by which it can see nearby objects as well as faraway objects by changing its focal length is called its power of accommodation.
The power of the eye by which it can see nearby objects as well as faraway objects by changing its focal length is called its power of accommodation.
See lessConsider a circular loop of wire lying in the plane of the table. Let the current pass through the loop clockwise. Apply the right-hand rule to find out the direction of the magnetic field inside and outside the loop.
Current is flowing clockwise through a circular loop. The direction of magnetic field around the conductor can be known by using the right hand thumb rule. As the figure shows, the magnetic field would be towards the plane of the paper when it is inside the loop. On the other hand, the magnetic fielRead more
Current is flowing clockwise through a circular loop. The direction of magnetic field around the conductor can be known by using the right hand thumb rule. As the figure shows, the magnetic field would be towards the plane of the paper when it is inside the loop. On the other hand, the magnetic field would be away from the paper when it is outside the loop.
See lessWhy don’t two magnetic field lines intersect each other?
If the field lines would cross each other then the direction of field line would change at the point of crossing which is practically impossible. Hence, two magnetic field lines never intersect each other.
If the field lines would cross each other then the direction of field line would change at the point of crossing which is practically impossible. Hence, two magnetic field lines never intersect each other.
See lessList the properties of magnetic field lines.
Properties of magnetic field lines: (a) Magnetic field lines follow the direction from the north pole to the south pole. (b) Magnetic field lines always show concentric pattern. (c) Magnetic field lines do not cross one another. (d) Closer the field lines; stronger is the magnetic field and vice-verRead more
Properties of magnetic field lines:
See less(a) Magnetic field lines follow the direction from the north pole to the south pole.
(b) Magnetic field lines always show concentric pattern.
(c) Magnetic field lines do not cross one another.
(d) Closer the field lines; stronger is the magnetic field and vice-versa is also true.
(e) Magnetic field lines are closer near the poles; which shows greater strength of magnetic field near the poles.
Why does a compass needle get deflected when brought near a bar magnet?
When a compass needle is brought near a bar magnet, the compass needle experiences a deflection. This happens because of interaction of magnetic fields of the compass needle and the bar magnet.
When a compass needle is brought near a bar magnet, the compass needle experiences a deflection. This happens because of interaction of magnetic fields of the compass needle and the bar magnet.
See lessWhat are the environmental consequences of the increasing demand for energy? What steps would you suggest to reduce energy consumption?
Environmental consequences of increasing demand for energy are as follows: 1.Use of fossil fuels is increasing air pollution which is not good for our health. 2. Air pollution is causing much damage to the ecosystem. 3. Greenhouse effect has resulted in global warming which is manifesting itself inRead more
Environmental consequences of increasing demand for energy are as follows:
1.Use of fossil fuels is increasing air pollution which is not good for our health.
2. Air pollution is causing much damage to the ecosystem.
3. Greenhouse effect has resulted in global warming which is manifesting itself in strange changes in the weather pattern around the world.
4. Too much exploitation of fossil fuels is going to create a situation when there would be not fossil fuel.
Steps to reduce energy consumption:
1. Judicious use of energy is the only way.
2. Use public transport instead of private modes of transport.
3. Use bicycle whenever possible.
4. Walk for short distance commute.
5. Avoid unnecessary use of modern gadgets which consume lot of energy.
6. Get a solar water heater installed for winter.
See lessWhat are the advantages and disadvantages of using a solar cooker? Are there places where solar cookers would have limited utility?
Advantages of Solar Cooker: - They are environment friendly. - Use of a solar cooker does not involve recurring expenses on fuel. Disadvantages of Solar Cooker: - Solar cooker is very slow. - Solar cooker can work only during summer months and is useless during winters and on cloudy days. - Solar coRead more
Advantages of Solar Cooker:
– They are environment friendly.
– Use of a solar cooker does not involve recurring expenses on fuel.
Disadvantages of Solar Cooker:
– Solar cooker is very slow.
– Solar cooker can work only during summer months and is useless during winters and on cloudy days.
– Solar cooker can be useful at those places which receive plenty of sunshine. This is useless in colder climates.
See less