Material: Copper and aluminium wires, glass rod,rubber. Make connection as shown in figure 3.8. First connect a copper wire betweenpoints A and B and measure the currentinthe circuit.Thenin place of the copper wire, connect aluminium wire, glass rod, rubber, etc one at a time and measure the current each time. Compare the values of the current in different cases

Give scientific reasons: Connecting wires in a circuit are made of copper and aluminium.

A copper wire of resistance 100 Q is connected to a battery of potential difference 25 V. What will be the current flowing through the wire? If the wire is replaced by aluminium wire, the current flowing through it decreases by 0.05 A. What is the resistance of aluminium wire used?

Read the given passage and answer the following questions: The home electrical connection consists of 'live','neutral' and 'earth wires. The 'live' and the 'neutral' wires have potential difference of 220 v. The earth ire is connected to ground. Due to a fault in the equipment or if the plastic coating on the 'live ' and the neutral wires gives away the two wires come in contact with each other and a large current flows through it producing heat . If any inflammable material (such as wood , cloth , plastic etc). exists around that place it can catch fire. Therefore a fuse wire is used as a precautionary measures. Name the two wires having potential difference of 220 v.

Read the given passage and answer the following questions: The home electrical connection consists of 'live','neutral' and 'earth wires. The 'live' and the 'neutral' wires have potential difference of 220 v. The earth ire is connected to ground. Due to a fault in the equipment or if the plastic coating on the 'live ' and the neutral wires gives away the two wires come in contact with each other and a large current flows through it producing heat . If any inflammable material (such as wood , cloth , plastic etc). exists around that place it can catch fire. Therefore a fuse wire is used as a precautionary measures. What is short circuit?

Read the given passage and answer the following questions: The home electrical connection consists of 'live','neutral' and 'earth wires. The 'live' and the 'neutral' wires have potential difference of 220 v. The earth ire is connected to ground. Due to a fault in the equipment or if the plastic coating on the 'live ' and the neutral wires gives away the two wires come in contact with each other and a large current flows through it producing heat . If any inflammable material (such as wood , cloth , plastic etc). exists around that place it can catch fire. Therefore a fuse wire is used as a precautionary measures. Write the function of a fuse?

Two wires shown in the figure are connected in a series circuit and the same amount of current of 10A passes through both, but in opposite directions seperation between the two wires is 8 mm. The length AB is S = 22 cm. Obtain the direction and magnetic field due to current in wire 2 on the section AB of wire 1. Also obtain the magnetic and direction of the force on wire 1. (mu_0=4pixx10^-7TmA^-1) .

Two resistances 2 ohm and 3 ohm are connected across the two gaps of the metre bridge as shown in the figure .Calculate the current through the cell when the bridge is balanced and the specific resistance of the material of the metre bridge wire. Given the resistance of the bridge wire is 1.49 ohm and its diameter is 0.12 cm.

Take the inside tray of a used up match box and place a small magnetic needle inside the tray . Now take a long connecting wire and wind it around the tray . Complete the electric circuit ny connecting in it , this wire , electric cell , plug key and a bulb as shown in the below figure .: Mark the position of the magnetic needle . take a bar magnet near to the magnetic needle . keep looking at the needle and close the plug key . the bulb will light up , and you will realize that the current has started flowing . does the magnetic needle change its position ? :

The magnitude of current density in a copper wire is 500 A//cm^2 . If the number of free electrons per cm^3 of copper is 8.47 xx 10^22 , calculate the drift velocity of the electrons through the copper wire (charge on an e = 1.6 xx 10^-19 C).