Why chromium is used for electroplating? Why the objects which have chromium plating are not made of chromium itself? Open Answer »
Why chromium is used for electroplating? Why the objects which have chromium plating are not made of chromium itself? Open Answer »
You are provided with a magnetic compass, an empty matchbox, a battery of two cells and connecting wires. Using these objects how will you make a tester for testing an electric circuit? Draw the necessary circuit diagram and explain. Open Answer »
Observing that the bulb does not glow in the circuit shown below in A, Boojho changed the circuit as shown in B. He observed deflection in the magnetic compass. a. What does the deflection in magnetic compass indicate? b. Why did the bulb not glow in A? c. What would be the effect of increase in the number of turns in the coil wound around the magnetic compass in B? d. What will be observed if the number of cells is increased in the circuit shown in B? Open Answer »
Boojho made the circuit shown alongside. He wanted to observe what happens when an electric current is passed through water. But he forgot to add a few drops of lemon juice to water. Will it make any difference to his observations? Explain. Open Answer »
Observe the circuit given below. Boojho set up this circuit for purification of copper. What will be the nature of a. plate A, b. plate B, c. the solution? Open Answer »
An electric current is passed through a conducting solution. List four possible observations. Open Answer »
Observe the following circuit given below. Current does not flow in the circuit if there is a gap between the two wires. Does it indicate that air is a poor conductor of electricity? Does air never conduct electricity? Explain. Open Answer »
In the circuit given below, Boojho observed that copper is deposited on the electrode connected to the negative terminal of the battery. Paheli tried to repeat the same experiment. But she could find only one copper plate. Therefore she took a carbon rod as negative electrode. Will copper be still deposited on the carbon rod? Explain your answer. Open Answer »