Electric Current & Light Practice Questions PDF

## Electric Current - The elements of an electric current include cells, wires, bulbs and electric circuit. - A switch is a device which enables us to make or break the electric circuit. - An electric bulb has a filament connected to its terminals. - A substance that allows electricity to flow thr...

## Electric Current - The elements of an electric current include cells, wires, bulbs and electric circuit. - A switch is a device which enables us to make or break the electric circuit. - An electric bulb has a filament connected to its terminals. - A substance that allows electricity to flow through it is a conductor of electricity. All metals and graphite are conductors. - An insulator does not allow the flow of current through them. Plastics, paper, rubber, wood, etc. are insulators. - We need to protect ourselves from dangerous and painful electric shocks. ### Practice Zone #### Objective Type A. Select and tick (✔) the correct answer : 1. Which of the following conducts electricity? - An eraser - A plastic ruler - An iron nail - A plastic jug 2. Which of these appliances in your house is not run by electricity? - Geyser - Gas burner - Air conditioner - Music system 3. In an electric cell, chemical energy is converted into: - Electrical energy - Mechanical energy - Kinetic energy - Sound energy 4. How many terminals are there in a dry cell? - One - Three - Four - Two B. Fill in the blanks : 1. Electricity in motion is called current. 2. A bulb is an electrical appliance which glows on passing electric current. 3. The pathway through which electrons move is called an electric circuit. 4. An electric switch is a device that is used to open and close an electric circuit. 5. Plastic and rubber are used to cover electric wires. C. Match the following : | Column A | Column B | |-------------------------|-----------------------| | Electric cell | Combination 2 | | Battery | Current 4 | | Human body | Source of electrical energy 1 | | Flow of charge | Insulator 6 | | Electric circuit | Conductor of electricity 3 | | Wood | Complete the Path for the flow of current 5 | #### Subjective Type A. Very short answer questions : 1. What is electric current? 2. Define a torch. 3. When is a circuit said to be open? 4. What is an insulator? B. Short answer questions : 1. What is an electric circuit? 2. What do you mean by a closed circuit? 3. What is a battery? 4. Name the elements of an electric current. 5. Why are electric wires insulated? C. Long answer questions : 1. Draw a diagram showing the lighting up of a bulb with an electric cell. 2. Draw an electric circuit and explain its working. 3. What is the difference between insulators and conductors? Give three examples of each. ## Light ### Practice Zone #### Objective Type A. Select and tick (✔) the correct answer : 1. Which of the following is not an artificial source of light? - Candle - Electric lamp - Sun - Gas 2. This is non-luminous : - Earth - Sun - Tubelight - Torch 3. Which of the following objects casts a weak shadow? - Opaque - Translucent - Transparent - All of these 4. This is a transparent object : - Cardboard - Steel - Pencil - Glass B. Fill in the blanks : 1. Natural sources of light occur in nature. 2. The objects which give out their own light are called luminous objects. 3. Light always travels in a straight line. 4. A pinhole camera is based on the principle of rectilinear propagation of light. 5. Plane mirrors are used in signalling by armed forces. C. Write true or false : 1. Shadows can be seen even in dark. (True) 2. Sun is a luminous object. (True) 3. Light travels in straight lines. (True) 4. Shadow is exactly the same shape as the object. (False) 5. Glass is a translucent object. (True) #### Subjective Type A. Very short answer questions : 1. What is light? 2. Define translucent objects. 3. What is a pinhole camera? 4. What do you mean by an object? 5. Give any one use of plane mirror. B. Short answer questions : 1. What are translucent objects? Give two examples. 2. When is a shadow formed? 3. What do you mean by rectilinear propagation of light? 4. On what principle is the pinhole camera based? 5. Name non-luminous objects. C. Long answer questions : 1. It is said that a pinhole camera exists in nature. Explain. 2. With the help of an experiment show that light travels in straight lines. 3. Write down difference between an image and a shadow. 4. What do you understand by reflection of light? 5. Write a note on the working of a periscope.