Sulphur is an electrical insulator, but it can be made to conduct electricity if a very bright light shines on it. A very bright light shines onto a small circular area in the centre of the charged slab of sulphur. The pattern of charge on the sulphur alters. The simplified diagram represents the new pattern of charge.
Explain why the pattern alters in this way.
Important Questions on Chemical Effects of Electric Current
Ram and friends constructed a simple circuit as shown below. A compass was placed near the circuit as shown. Which of these statements is TRUE?
A switch controls whether electricity flows in a circuit or not. When a switch is in OFF condition, no current flows through the circuit. When a switch is in ON condition, current flows through the circuit.
In the figure given below, S1, S2, S3 and S4 are switches. Under what case will the bulb glow?
Rekha was travelling in a diesel train. She wanted to charge her mobile phone. A train with a diesel engine is not connected to any external source of electricity while it is moving. What is the MAIN source of the electricity on which the fans and lights in the coaches run?
A large number of solar cells are joined together to form a solar panel. In the solar panel shown here, one form of energy is converted into another form of energy.
An example of a device in which the energy conversion is opposite to that of the solar panel is
A battery is a device that stores chemical energy and converts it to electrical energy. The chemical reactions in a battery involve the flow of electrons from one material (electrode) to another, through an external circuit. The flow of electrons provides an electric current that can be used to do work.
Your task is to generate electricity through a chemical reaction. Which among the following groups would you use?
A coil is wrapped loosely around a cylindrical wooden piece and its ends are connected to a battery as shown. In which case will the compass needle placed near the coil deflect when the circuit is closed?
Given below is a diagrammatic representation of an electromagnet. The strength of the magnetic field between the poles of the electromagnet would be UNCHANGED if the
