(English Medium) ICSE Class 10 - CISCE Question Bank Solutions for Physics

Why is the focal length of the lens, used as a magnifying glass, kept short?

Will the image formed by a magnifying glass be real or virtual?

What information we seek by the linear magnification of the image when it is positive or negative?

Define magnification produced by a lens. State its unit.

Name the lens for which magnification can be 1. For what position of the object will the magnification be 1?

Name the lens for which magnification is always less than 1.

A convex lens produces on a screen an image twice the size of the object. If the position of image and object be interchanged, what will be the magnification then?

How is the magnification (m) produced by a lens related to the object distance (u) and the image distance (v)?

An object is placed in front of a lens between its optical centre and the focus and forms a virtual, erect, and diminished image. Draw a ray diagram to show the formation of the image with the above-stated characteristics.

Show with the help of a ray diagram, the path of the ray when incident normally on the first surface of the glass block, through the block and the liquid.

Draw a neat diagram to explain the action of a convergent (convex) lens as a reading glass (or magnifying glass). State the characteristics of the image formed.

What is a simple microscope or a magnifying glass? Draw a ray diagram to show its function.

Copy and complete the following ray diagram.

Copy and complete the following ray diagram.

An erect, magnified, and a virtual image is formed when an object is placed between the optical centre and principal focus of a lens.
(i) Name the lens.
(ii) Draw a ray diagram to show the formation of the image with the above-stated characteristics.

An object AB is placed between 2F₁ and F₁ on the principal axis of a convex lens as shown in the diagram. Copy the diagram and using three rays starting from point A, obtain the image of the object formed by the lens.

What is a magnifying glass (or a simple microscope)? Draw a ray diagram to show how a convex lens may be used as a magnifying glass. Where should the object be placed? State three characteristics of the image formed.

(i) Draw a ray diagram to show how the lens can be used as a ‘magnifying glass’? State the nature of the lens.
(ii) In what respect does the image in (i) above different from the image formed by a concave lens?

The above picture shows a mother pushing her daughter sitting on a swing. The swing is going through the positions A, B, C where A and C are extreme positions and B is the mean position.

1. Which is the right position i.e. at A, B or C, for the mother to give a constant periodic push to the swing every time in the forward direction to increase the amplitude of the swing?  (1)
2. Name the phenomenon involved in this.  (1)
3. Explain with this example how this phenomenon helps to increase the amplitude of the swing.  (2)

Write an expression for the magnifying power of a simple microscope. How can it be increased?