Physics 5054 · O Level
Thin lenses
64 practice questions on Thin lenses, with worked solutions and instant marking.
When a thin converging lens is used as a magnifying glass, an image is produced. Which description of the image is correct?
May/June 2015
A thin converging lens is acting as a magnifying glass and produces an image. Which description of the image is correct?
May/June 2015
Which measurement is the focal length of the lens shown in the diagram?
May/June 2016
Which distance represents the focal length of the lens in the diagram?
May/June 2016
Light rays from a ray-box travel through three lenses positioned at $1$, $2$ and $3$. What kind of lens is fitted at each position?
May/June 2016
Distant objects can be seen sharply, whereas nearby objects look blurred. Fig. 5.1 shows three rays from one point on a near object as they travel through the person’s eye. Refraction of the light as it enters the eye is ignored.
May/June 2016
Fig. 4.1 shows a converging lens, an object O and the image I formed by the lens.
May/June 2017
The diagram illustrates the routes taken by two rays from the top of an object passing through a lens. The image is seen from the side of the lens opposite the object. In what ways is the image different from the object?
May/June 2018
A converging lens has a focal length of 3.0 cm. An object that is 2.0 cm tall is positioned 5.0 cm from the centre of the lens. Fig. 6.1 displays the object and lens setup.
May/June 2018
A parallel beam of light strikes a thin diverging lens. The focal length of the lens is FL, as illustrated in the diagram. Which ray diagram shows the beam after it has passed through the lens?
May/June 2019
An object is positioned at a distance from a converging lens equal to 2 times the focal length of the lens. Which statement about the image is correct?
May/June 2019
The lens shown in the diagram forms an image $I$ of the object $O$. Why does this not represent the ray diagram for a photographic enlarger?
May/June 2019
Which statement correctly describes human vision?
May/June 2021
An object with height $1.5\,\text{cm}$ stands in front of a converging lens with focal length $2.0\,\text{cm}$. The setup is illustrated on the full-scale ray diagram. What linear magnification does the lens produce?
May/June 2021
In which optical instrument is the separation between the object and the lens smaller than the focal length of the lens?
May/June 2021
Fig. 5.1 presents part of the ray diagram for a lens acting as a magnifying glass. Three rays travel from the top of object O. The points marked F are one focal length away from the lens. Fig. 5.1 shows a converging lens, and the rays are labelled R.
May/June 2021
In Fig. 2.1, a student is determining the focal length of a convex lens, and the apparatus has been arranged as shown.
May/June 2021
A student determines the focal length $f$ of a convex lens.
May/June 2021
An object is seen through a thin converging lens. The diagram illustrates the routes of two rays travelling from the top of the object to an eye. How is the image different from the object?
May/June 2022
An object is seen through a thin converging lens. The diagram shows the paths taken by two rays from the top of the object to an eye. In what ways does the image differ from the object?
May/June 2022
The virtual reality headset in Fig. 6.1 includes a display and a lens, as shown in Fig. 6.2. For the lens, the display acts as the object. The lens works like a magnifying glass and produces a virtual image of the display.
May/June 2023
A student uses a converging lens to examine the image it produces.
May/June 2023
Which diagram illustrates light rays passing through a converging lens?
May/June 2024
Which diagram shows how light from a distant object produces an image in a normal eye?
May/June 2024
A thin converging lens is used as a magnifying glass. Which row shows the image’s nature and an expression for the linear magnification?
May/June 2024
A student is determining the focal length of a lens.
May/June 2024
A student is working with a converging (convex) lens and wants to find its focal length. The focal length $f$ of a lens is obtained from the equation: $f = \frac{uv}{u + v}$ where $u$ is the separation between the object and the lens and $v$ is the separation between the focussed image of the object and the lens.
May/June 2024
Light rays from a ray-box travel through three lenses fitted at positions $1$, $2$ and $3$. What kind of lens is used at each position?
May/June 2025
When a converging lens is used as a magnifying glass, what type of image is produced?
May/June 2025
An object $O$ is positioned between a converging lens and one principal focus $F$ of the lens. What magnification is produced by the image formed?
May/June 2025
An object is observed through a converging lens. The diagram illustrates the paths followed by two rays travelling from the top of the object to an eye. In what ways does the image differ from the object?
Oct/Nov 2015
A lit candle is set near a thin converging lens, and the candle is treated as the object. A white, vertical screen is shifted to a point on the side of the lens opposite the candle. Fig. 6.1 is a full-size, graph-paper drawing of the lens and the screen. The focal length of the lens is 2.4 cm. The screen is 7.2 cm from the centre of the lens. A sharply focused, inverted image of the candle is formed on the screen, as shown in Fig. 6.1.
Oct/Nov 2015
A student carries out an experiment to determine an accurate value for the focal length of a converging lens. His school possesses lenses with focal lengths 10 cm and 15 cm. He is handed a lens taken from a packet marked ‘focal length 10 cm’.
Oct/Nov 2015
The diagram shows a convex lens producing an image I of an object O. It is not drawn to scale. What is the focal length of the lens?
Oct/Nov 2016
The scale diagram shows that a lens forms a magnified image. What is the linear magnification produced by the lens?
Oct/Nov 2016
A lens is used to form a magnified image, as illustrated by the scale diagram. What is the linear magnification produced by the lens?
Oct/Nov 2016
A girl has long-sightedness. Which of the following statements is correct?
Oct/Nov 2016
What is the lens called, and what shape does it have, for correcting short sight?
Oct/Nov 2017
An object is positioned before a converging lens. The lens produces a magnified image of the object on a screen. Which statement is correct?
Oct/Nov 2017
The ray diagrams, X and Y, illustrate two ways a thin converging lens can create an image larger than its object. Which devices use a lens arranged as in diagram X and as in diagram Y?
Oct/Nov 2017
In Fig. 4.1, AB is a converging lens. The object PQ is positioned so that end Q lies on the principal axis ST of the lens.
Oct/Nov 2017
The diagram depicts a thin converging lens with focal length $f$. At what position should an object be placed so that a real image forms at the location shown?
Oct/Nov 2018
The diagram represents a thin converging lens with focal length $f$. At what position should an object be placed so that a real image is formed at the location shown?
Oct/Nov 2018
A student determines the focal length of a convex lens. He assembles the apparatus shown in Fig. 2.1. He positions the lens some distance from the illuminated object. He slides the screen until a clear image of the object is formed on the screen.
Oct/Nov 2018
An object stands in front of a converging lens with focal length $4.0\,\text{cm}$. The image height is $6.0\,\text{cm}$. The setup is illustrated on the scale diagram. What is the linear magnification produced by the lens?
Oct/Nov 2019
Visible light forms one part of the electromagnetic spectrum.
Oct/Nov 2019
A student wants to determine the focal length $f$ of a lens. An arrow-shaped slit cut in a card is used as the object, as shown in Fig. 1.1. The object is positioned at one end of a metre rule, and the lens is held a distance $u$ from the object, as illustrated in Fig. 1.2. The slit is lit from behind by a lamp. A screen is then set on the metre rule until a sharp, focused image of the arrow is produced. The distance $v$ from the lens to the screen is then measured.
Oct/Nov 2019
A parallel beam of light falls on a thin converging lens. F is one of the lens’s focal points. Which ray diagram shows the light after it has travelled through the lens?
Oct/Nov 2020
The lens is a thin converging type and is made from a transparent substance with refractive index 1.4.
Oct/Nov 2020
Two light rays travel through a lens in region X. What kind of lens is located in region X, and what kind of image is produced?
Oct/Nov 2021
Which statement is true about a girl who is long-sighted?
Oct/Nov 2021
A torn piece of paper from an exercise book is shown. It reads: "The object is farther from the lens than the focal point and the image is upside down." Which process is being described?
Oct/Nov 2021
A girl has long-sightedness. Which statement is correct?
Oct/Nov 2021
A thin converging lens produces a real, sharply focused image of an object, as shown. Which distance is the same as the focal length of the lens?
Oct/Nov 2022
Which ray diagram illustrates the action of a diverging lens?
Oct/Nov 2022
A parallel beam of light moving through air falls on a glass lens. As shown in Fig. 8.1, the beam is at right angles to the lens. The dashed line P shows where the lens is placed. The lens centre is marked by dot C.
Oct/Nov 2022
An object is positioned in front of a converging lens with focal length $4.0\,\text{cm}$. The image height is $6.0\,\text{cm}$. The setup is illustrated in the scale diagram. What is the linear magnification created by the lens?
Oct/Nov 2023
A lens is used to form a magnified image, as shown in the scale diagram. Determine the linear magnification produced by the lens.
Oct/Nov 2023
A student with short-sightedness is viewing a distant object. Which row gives the position of the image in a short-sighted eye, together with the type of lens used to correct short-sightedness?
Oct/Nov 2024
Some glass lenses act as converging lenses, whereas others act as diverging lenses. Fig. 5.1 presents the cross-section of a converging lens, the principal axis and the two principal focuses (focal points) $F_1$ and $F_2$ on a full-scale grid.
Oct/Nov 2024
A student carries out an investigation into the image produced by a converging lens.
Oct/Nov 2024
An object O is positioned close to a thin converging lens. The diagram shows three light rays from the object travelling through the lens. Which row states the image that is produced and indicates the location of a principal focus (focal point) of the lens?
Oct/Nov 2025
A student carries out an investigation with four thin lenses. These lenses are used to form focused images of four different objects. The student measures the image length and the object length. The results are given in the table. In which case is the magnification produced the greatest?
Oct/Nov 2025
Fig. 4.1 illustrates a ray of light hitting the left-hand face of a thin converging glass lens. Diagram labels: ray of light, lens. An object O, with height 1.8 cm, is positioned 2.2 cm to the left of the lens centre. Fig. 4.2 is a full-size diagram showing the converging lens, its principal axis and its two principal focuses, F1 and F2.
Oct/Nov 2025