3. Where should an object be placed in front of a convex lens to get a real image of the size of the object? -Physics-10

3. Where should an object be placed in front of a convex lens to get a real image of the size of the object? -Physics-10
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1 Answer

Answer :

(b) The object should be placed at twice the focal length
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Related questions

2. A convex lens forms a real and inverted image of a needle at a distance of 50 cm from it. Where is the needle placed in front of the convex lens if the image is equal to the size of the object? -Physics-10

Description : 2. A convex lens forms a real and inverted image of a needle at a distance of 50 cm from it. Where is the needle placed in front of the convex lens if the image is equal to the size of the object? -Physics-10

Last Answer : The position of the image should be at 2F since the image is the real and same size. It is given that the image of the needle is formed at a distance of 50 cm from the convex lens. Therefore, the needle is ... (u) = - 50 cm Image distance, (v) = 50 cm Focal length = f According to the lens formula,

14. An object 5 cm is placed at a distance of 20 cm in front of a convex mirror of radius of curvature 30 cm. Find the position, nature and size of the image. -Physics-10

Description : 14. An object 5 cm is placed at a distance of 20 cm in front of a convex mirror of radius of curvature 30 cm. Find the position, nature and size of the image. -Physics-10

Last Answer : Object distance (u) = - 20 cm Object height (h) = 5 cm Radius of curvature (R) = 30 cm Radius of curvature = 2 Focal length R = 2f f = 15 cm According to the mirror formula, ... image height indicates that the image formed is erect. Hence, the image formed is erect, virtual, and smaller in size.

2. A concave mirror produces three times magnified (enlarged) real image of an object placed at 10 cm in front of it. Where is the image located? -Physics-10

Description : 2. A concave mirror produces three times magnified (enlarged) real image of an object placed at 10 cm in front of it. Where is the image located? -Physics-10

Last Answer : Magnification produced by a spherical mirror: Object distance (u) = – 10 cm v = 3 × (- 10) = – 30 cm Therefore, the negative sign indicates that an inverted image is formed in front of the given concave mirror at a distance of 30 cm.

9. One-half of a convex lens is covered with a black paper. Will this lens produce a complete image of the object? Verify your answer experimentally. Explain your observations. -Physics-10

Description : 9. One-half of a convex lens is covered with a black paper. Will this lens produce a complete image of the object? Verify your answer experimentally. Explain your observations. -Physics-10

Last Answer : Yes, it will produce a complete image of the object, as shown in the figure. This can be verified experimentally by observing the image of a distant object like a tree on a screen when the ... the lens is covered with a black paper. However, the intensity or brightness of the image will reduce.

15. An object of size 7.0 cm is placed at 27 cm in front of a concave mirror of focal length 18 cm. At what distance from the mirror should a screen be placed so that a sharply focused image can be obtained? Find the size and nature of the image. -Physics-10

Description : 15. An object of size 7.0 cm is placed at 27 cm in front of a concave mirror of focal length 18 cm. At what distance from the mirror should a screen be placed so that a sharply focused image can be obtained? Find the size and nature of the image. -Physics-10

Last Answer : Object distance (u) = – 27 cm Object height (h) = 7 cm Focal length (f) = – 18 cm According to the mirror formula, The negative value of image height indicates that the image formed is inverted.

12. An object is placed at a distance of 10 cm from a convex mirror of focal length 15 cm. Find the position and nature of the image. -Physics-10

Description : 12. An object is placed at a distance of 10 cm from a convex mirror of focal length 15 cm. Find the position and nature of the image. -Physics-10

Last Answer : Focal length of convex mirror (f) = +15 cm Object distance (u) = - 10 cm According to the mirror formula, The image is located at a distance of 6 cm from the mirror on the other ... and a value of less than 1 of magnification indicates that the image formed is virtual and erect and diminished.

11. A concave lens of focal length 15 cm forms an image 10 cm from the lens. How far is the object placed from the lens? Draw the ray diagram. -Physics-10

Description : 11. A concave lens of focal length 15 cm forms an image 10 cm from the lens. How far is the object placed from the lens? Draw the ray diagram. -Physics-10

Last Answer : Focal length of concave lens (OF1), f = – 15 cm Image distance, v= – 10 cm According to the lens formula, The negative value of u indicates that the object is placed 30 cm in front of the lens. This is shown in the following ray diagram.

10. An object 5 cm in length is held 25 cm away from a converging lens of focal length 10 cm. Draw the ray diagram and find the position, size and the nature of the image formed. -Physics-10

Description : 10. An object 5 cm in length is held 25 cm away from a converging lens of focal length 10 cm. Draw the ray diagram and find the position, size and the nature of the image formed. -Physics-10

Last Answer : Height of the Object, h0 = 5 cm Distance of the object from converging lens, u = -25 cm Focal length of a converging lens, f = 10 cm Using lens formula, Thus, the image is inverted and formed at a distance of 16.7 cm behind the lens and measures 3.3 cm. The ray diagram is shown below.

A convex lens has a focal length of 10 cm. At what distance from the lens should the object be placed so that it forms a real and inverted image 20 cm away from the lens? What would be the size of the image formed if the object is 2 cm high? With the help of a ray diagram show the formation of the image by the lens in this case. -Physics

Description : A convex lens has a focal length of 10 cm. At what distance from the lens should the object be placed so that it forms a real and inverted image 20 cm away from the lens? What would be the size of ... ? With the help of a ray diagram show the formation of the image by the lens in this case. -Physics

Last Answer : This is the Answe:

Draw the ray diagram in each case to show the position and nature of the image formed when the object is placed: (i) at the centre of curvature of a concave mirror (ii) between the pole P and focus F of a concave mirror (iii) in front of a convex mirror (iv) at 2F of a convex lens (v) in front of a concave lens -Physics

Description : Draw the ray diagram in each case to show the position and nature of the image formed when the object is placed: (i) at the centre of curvature of a concave mirror (ii) between the pole P and focus F of ... front of a convex mirror (iv) at 2F of a convex lens (v) in front of a concave lens -Physics

Last Answer : Answer. Nature of image: Real, inverted and same size image is formed at the centre of curvature. Nature of image: Virtual, enlarged and erect image is formed behind the mirror. Nature of image: Virtual ... : Virtual, erect and diminished image is formed between O and F on the same side of object.

An object 2 cm high is placed at a distance of 64 cm from a white screen. On placing a convex lens at a distance of 32 cm from the object it is found that a distinct image of the object is formed on the screen. What is the focal length of the convex lens and size of the image formed on the screen? Draw a ray diagram to show the formation of the image in this position of the object with respect to the lens. -Physics

Description : An object 2 cm high is placed at a distance of 64 cm from a white screen. On placing a convex lens at a distance of 32 cm from the object it is found that a distinct image of the object ... diagram to show the formation of the image in this position of the object with respect to the lens. -Physics

Last Answer : Since, object-screen distance is double of object-lens separation, the object is at a distance of 2f from the lens and the image should be of the same size of the object.

We wish to obtain an erect image of an object, using a concave mirror of focal length 15 cm. What should be the range of distance of the object from the mirror? -Physics-10

Description : We wish to obtain an erect image of an object, using a concave mirror of focal length 15 cm. What should be the range of distance of the object from the mirror? -Physics-10

Last Answer : Range of the distance of the object = 0 to 15 cm from the pole of the mirror. Nature of the image = virtual, erect, and larger than the object.

2. The image formed by a concave mirror is observed to be virtual, erect and larger than the object. Where should be the position of the object? -Physics-10

Description : 2. The image formed by a concave mirror is observed to be virtual, erect and larger than the object. Where should be the position of the object? -Physics-10

Last Answer : (d) The position of the object should be between the pole of the mirror and its principal focus.

3. Name the mirror that can give an erect and enlarged image of an object. -Physics-10

Description : 3. Name the mirror that can give an erect and enlarged image of an object. -Physics-10

Last Answer : The mirror that can give an erect and enlarged image of an object is Concave Mirror.

An object 50 cm tall is placed on the principal axis of a convex lens. Its 20 cm tall image is formed on the screen placed at a distance of 10 cm from the lens. Calculate the focal length of the lens. -Physics

Description : An object 50 cm tall is placed on the principal axis of a convex lens. Its 20 cm tall image is formed on the screen placed at a distance of 10 cm from the lens. Calculate the focal length of the lens. -Physics

Last Answer : The focal length' of convex length is 7.14 cm. Solution: The given quantities are Height of the object h = 50 cm Height of the image formed h' = -20 cm Image distance v = 10 cm The image ... object distance will be So the focal length will be Thus the focal length of the convex lens is 7.14 cm

1. Find the focal length of a convex mirror whose radius of curvature is 32 cm. -Physics-10

Description : 1. Find the focal length of a convex mirror whose radius of curvature is 32 cm. -Physics-10

Last Answer : Radius of curvature (R) = 32 cm Radius of curvature = 2 × Focal length (f) R= 2f f = R/2 = 32/2 = 16 Therefore, the focal length of the given convex mirror is 16 cm.

4. Why do we prefer a convex mirror as a rear-view mirror in vehicles? -Physics-10

Description : 4. Why do we prefer a convex mirror as a rear-view mirror in vehicles? -Physics-10

Last Answer : Convex mirror is preferred as a rear-view mirror in cars and vehicles as it gives a wider field of view, which helps the driver to see most of the traffic behind him. Convex mirrors always form an erect, virtual, and diminished image of the objects placed in front of it.

A what distance must an object be placed from convex lens of power 4D to obtain a real image three times the size of the object ?

Description : A what distance must an object be placed from convex lens of power 4D to obtain a real image three times the size of the object ?

Last Answer : A what distance must an object be placed from convex lens of power 4D to obtain a real image three times the size of the object ?

17. A doctor has prescribed a corrective lens of power +1.5 D. Find the focal length of the lens. Is the prescribed lens diverging or converging? -Physics-10

Description : 17. A doctor has prescribed a corrective lens of power +1.5 D. Find the focal length of the lens. Is the prescribed lens diverging or converging? -Physics-10

Last Answer : Power of lens (P) = 1/f P = 1.5D f = 1/1.5 = 10/15 = 0.66 m A convex lens has a positive focal length. Therefore, it is a convex lens or a converging lens.

16. Find the focal length of a lens of power -2.0 D. What type of lens is this? -Physics-10

Description : 16. Find the focal length of a lens of power -2.0 D. What type of lens is this? -Physics-10

Last Answer : Power of lens (P) = 1/f P = -2D f = -1/2 = -0.5 m A concave lens has a negative focal length. Therefore, it is a concave lens.

4. A spherical mirror and a thin spherical lens have a focal length of -15 cm. The mirror and the lens are likely to be -Physics-10

Description : 4. A spherical mirror and a thin spherical lens have a focal length of -15 cm. The mirror and the lens are likely to be -Physics-10

Last Answer : (a) Both are likely to be concave.

1. Which one of the following materials cannot be used to make a lens? -Physics-10

Description : 1. Which one of the following materials cannot be used to make a lens? -Physics-10

Last Answer : (d) Clay cannot be used to make a lens because if the lens is made up of clay the light rays cannot pass through it

3. Find the power of a concave lens of focal length 2 m. -Physics-10

Description : 3. Find the power of a concave lens of focal length 2 m. -Physics-10

Last Answer : Focal length of concave lens (f) = 2 m Power of lens (P) = 1/f = 1/ (-2) = -0.5D

1. Define 1 dioptre of power of a lens. -Physics-10

Description : 1. Define 1 dioptre of power of a lens. -Physics-10

Last Answer : Dioptre is the SI unit of power of lens is denoted by the letter D. 1 dioptre can be defined as the power of a lens of focal length 1 metre.

An object is placed beyond 2F, in front of a convex lens, image will be formed : (a) between F and 2F (b) at focus (c) at the centre of curvature (d) between focus and Optical centre

Description : An object is placed beyond 2F, in front of a convex lens, image will be formed : (a) between F and 2F (b) at focus (c) at the centre of curvature (d) between focus and Optical centre

Last Answer : (a) between F and 2F

When object is placed _______ in front of convex lens than image formed is virtual, erect, magnified and on same side beyond F . a) between optical centre and F b)At F c)between F and 2F d)2F

Description : When object is placed _______ in front of convex lens than image formed is virtual, erect, magnified and on same side beyond F . a) between optical centre and F b)At F c)between F and 2F d)2F

Last Answer : a) between optical centre and F

9. When is the force experienced by a current–carrying conductor placed in a magnetic field largest? -Physics-10

Description : 9. When is the force experienced by a current–carrying conductor placed in a magnetic field largest? -Physics-10

Last Answer : When the direction of the current is perpendicular to the direction of the magnetic field is when the force experienced is the largest.

12. Draw ray diagrams to represent the nature, position and relative size of the image formed by a convex lens for the object placed: -Chemistry-10

Description : 12. Draw ray diagrams to represent the nature, position and relative size of the image formed by a convex lens for the object placed: -Chemistry-10

Last Answer : Answer. hope this helps you

5. No matter how far you stand from a mirror, your image appears erect. The mirror is likely to be -Physics-10

Description : 5. No matter how far you stand from a mirror, your image appears erect. The mirror is likely to be -Physics-10

Last Answer : (d) The mirrors are likely to be either plane or convex

A convex lens is placed on an optical bench and is moved till it gives a real image of an object at a minimum distance of 80 cm from the latter. Find

Description : A convex lens is placed on an optical bench and is moved till it gives a real image of an object at a minimum distance of 80 cm from the latter. Find

Last Answer : A convex lens is placed on an optical bench and is moved till it gives a real image of an object ... cm from the lens, find the position of the image.

At what distance should an object be placed from a convex lens of focal langth `15 cm` to obtain an image three times the size of the object ?

Description : At what distance should an object be placed from a convex lens of focal langth `15 cm` to obtain an image three times the size of the object ?

Last Answer : At what distance should an object be placed from a convex lens of focal langth `15 cm` to obtain an image three times the size of the object ?

A concave lens has focal length of 20 cm. At what distance from the lens a 5 cm tall object be placed so that it forms an image at 15 cm from the lens? Also calculate the size of the image formed. -Physics

Description : A concave lens has focal length of 20 cm. At what distance from the lens a 5 cm tall object be placed so that it forms an image at 15 cm from the lens? Also calculate the size of the image formed. -Physics

Last Answer : Answer. I hope it helped you.

15. An object 2 cm high is placed at a distance of 64 cm from a white screen. On placing a convex lens at a distance of 32 cm from the object it is found that a distinct image of the object is formed on the screen. What is the focal length of the conve -Chemistry-10

Description : 15. An object 2 cm high is placed at a distance of 64 cm from a white screen. On placing a convex lens at a distance of 32 cm from the object it is found that a distinct image of the object is formed on the screen. What is the focal length of the conve -Chemistry-10

Last Answer : Since, object-screen distance is double of object-lens separation, the object is at a distance of 2f from the lens and the image should be of the same size of the object.

2. An object 50 cm tall is placed on the principal axis of a convex lens. Its 20 cm tall image is formed on the screen placed at a distance of 10 cm from the lens. Calculate the focal length of the lens. [All India] -Chemistry-10

Description : 2. An object 50 cm tall is placed on the principal axis of a convex lens. Its 20 cm tall image is formed on the screen placed at a distance of 10 cm from the lens. Calculate the focal length of the lens. [All India] -Chemistry-10

Last Answer : this is the answer for the respected question

An object is placed on the principal axis of a convex lens of focal length 10 cm. If the distance of the object from the lens is 30 cm, what is the distance of the image formed? (1) 20 cm (2) 15 cm (3) 30 cm (4) 10 cm

Description : An object is placed on the principal axis of a convex lens of focal length 10 cm. If the distance of the object from the lens is 30 cm, what is the distance of the image formed? (1) 20 cm (2) 15 cm (3) 30 cm (4) 10 cm

Last Answer : (2) 15 cm

In case of convex lens when the image formed is real, inverted and same size as the object then the object should have been at ______ position of lens. a) infinity b)focus c)2F d)between F and 2F

Description : In case of convex lens when the image formed is real, inverted and same size as the object then the object should have been at ______ position of lens. a) infinity b)focus c)2F d)between F and 2F

Last Answer : c)2F

An object is placed at `0.06` m from a convex lens of focal length `0.1`m. Calculate the position of the image?

Description : An object is placed at `0.06` m from a convex lens of focal length `0.1`m. Calculate the position of the image?

Last Answer : An object is placed at `0.06` m from a convex lens of focal length `0.1`m. Calculate the position of the image?

A student focuses the image of a candle flame, placed at about 2 m from a convex lens of focal length 10 cm, on a screen. After that he moves gradually the flame towards the lens and each time focuses its image on the screen. (a) In which direction does he move the lens to focus the flame on the screen? (b) What happens to the size of the image of the flame formed on the screen? (c) What difference is seen in the intensity (brightness) of the image of the flame on the screen? (d) What is seen on the screen when the flame is very close (at about 5 cm) to the lens?

Description : A student focuses the image of a candle flame, placed at about 2 m from a convex lens of focal length 10 cm, on a screen. After that he moves gradually the flame towards the lens and each time focuses its ... d) What is seen on the screen when the flame is very close (at about 5 cm) to the lens?

Last Answer : (a) The student moves the lens away from the screen to focus the image because on moving the candle towards the lens, the image distance increases. (b)The size of the image increases when the object ... on the screen. A virtual image is formed behind the candle on the same side of the screen.

What does OHM's law state? -Physics-10

Description : What does OHM's law state? -Physics-10

Last Answer : Ohm's Law given by Georg Ohm states that, at constant temperature, the Potential Difference is directly proportional to the Electric Current. Formula: V = IR

8. How does a solenoid behave like a magnet? Can you determine the north and south poles of a current–carrying solenoid with the help of a bar magnet? Explain. -Physics-10

Description : 8. How does a solenoid behave like a magnet? Can you determine the north and south poles of a current–carrying solenoid with the help of a bar magnet? Explain. -Physics-10

Last Answer : A solenoid is a long coil of circular loops of insulated copper wire. The magnetic field produced around the solenoid when the current is passed through it is similar to the magnetic field ... shows the arrangement of magnetic fields produced around the solenoid when current is passed through it.

7. List two methods of producing magnetic fields. -Physics-10

Description : 7. List two methods of producing magnetic fields. -Physics-10

Last Answer : Following are the methods of producing magnetic fields: By using a permanent magnet we can produce magnetic field and it can be visualized by spreading iron fillings on a white paper and keeping a ... conductors such as solenoid and circular loop can be used to see the presence of magnetic field.

6. State whether the following statements are true or false. -Physics-10

Description : 6. State whether the following statements are true or false. -Physics-10

Last Answer : False An electric motor converts electrical energy into mechanical energy. b. True An electric generator is a device that generates electricity by rotating a coil in a magnetic field. c. True A long ... lines. d. False Live wires have red insulation cover while the earth wire has green insulation.

At the time of short circuit, the current in the circuit reduces substantially. does not change. increases heavily. vary continuously. -Physics-10

Description : At the time of short circuit, the current in the circuit reduces substantially. does not change. increases heavily. vary continuously. -Physics-10

Last Answer : increases heavily When two naked wires in the circuit come in contact with each other, the amount of current flowing in the circuit increase abruptly resulting in short circuit.

4. The essential difference between an AC generator and a DC generator is that -Physics-10

Description : 4. The essential difference between an AC generator and a DC generator is that -Physics-10

Last Answer : AC generator has slip rings while the DC generator has a commutator. AC generators have two rings known as the slip rings while DC generators have two half rings known as the commutator. This is main difference between AC generator and DC generator.

3. The device used for producing electric current is called a -Physics-10

Description : 3. The device used for producing electric current is called a -Physics-10

Last Answer : generator The device used for producing electric current is known as generator. Generator converts mechanical energy to electric energy.

2. The phenomenon of electromagnetic induction is -Physics-10

Description : 2. The phenomenon of electromagnetic induction is -Physics-10

Last Answer : producing induced current in a coil due to relative motion between a magnet and the coil. The phenomenon of inducing current in a coil due to the relative motion between the coil and the magnet Is known as electromagnetic induction.

1. Which of the following correctly describes the magnetic field near a long straight wire? -Physics-10

Description : 1. Which of the following correctly describes the magnetic field near a long straight wire? -Physics-10

Last Answer : The field consists of concentric circles centered on the wire. The magnetic field near a long straight wire are concentric circles. Their centers lie on the wire.

3. What precaution should be taken to avoid the overloading of domestic electric circuits? -Physics-10

Description : 3. What precaution should be taken to avoid the overloading of domestic electric circuits? -Physics-10

Last Answer : A few of the precautions to be taken to avoid the overloading of domestic electric circuits are as follows: Connecting too many devices to a single socket should be avoided Using too many appliances at the same time should be avoided Faulty appliances should not be connected to the circuit

2. An electric oven of 2 kW power rating is operated in a domestic electric circuit (220 V) that has a current rating of 5 A. What result do you expect? Explain. -Physics-10

Description : 2. An electric oven of 2 kW power rating is operated in a domestic electric circuit (220 V) that has a current rating of 5 A. What result do you expect? Explain. -Physics-10

Last Answer : The current drawn by the electric oven can be calculated using the formula P = V × I I = P/V Substituting the values, we get I = 2000 W/220 V = 9.09 A The current drawn by the electric oven is 9.09 A which exceeds the safe limit of the circuit. This causes the fuse to melt and break the circuit.

1. Name two safety measures commonly used in electric circuits and appliances. -Physics-10

Description : 1. Name two safety measures commonly used in electric circuits and appliances. -Physics-10

Last Answer : The safety measured commonly used in electric circuits are as follows: Fuse Each circuit should be connected to a fuse because a fuse prevents the flow of excessive current through the circuit. ... to the ground by earthing and the people using the appliance is prevented from getting electrocuted.