Ch-13 Page No 224: Question 1: Why does a compass needle get deflected when brought near a bar magnet? Ch-13 Page No 228: Question 1: Draw magnetic field lines around a bar magnet. Ch-13 Question 2: List the properties of magnetic lines of force. Ch-13 Question 3: Why don’t two magnetic lines of force intersect each other? Ch-13 Page No 229: Question 1: Consider a circular loop of wire lying in the plane of the table. Let the current pass through the loop clockwise. Ch-13 Question 2: The magnetic field in a given region is uniform. Draw a diagram to represent it. Ch-13 Page No 230: Question 3: Choose the correct option. The magnetic field inside a long straight solenoid-carrying current (a) is zero Ch-13 Page No 231: Question 1: Which of the following property of a proton can change while it moves freely in a magnetic field? Ch-13 Page No 232: Question 2: In Activity 13.7 (page: 230), how do we think the displacement of rod AB will be affected if (i) current in rod AB is increased: Ch-13 Question 3: A positively-charged particle (alpha-particle) projected towards west is deflected towards north by a magnetic field. The direction of magnetic field is (a) towards south Ch-13 Page No 233: Question 1: State Fleming’s left-hand rule. Ch-13 Question 2: What is the principle of an electric motor? Ch-13 Question 3: What is the role of the split ring in an electric motor? Ch-13 Page No 236: Question 1: Explain different ways to induce current in a coil. Ch-13 Page No 237: Question 1: State the principle of an electric generator. Ch-13 Question 2: Name some sources of direct current. Ch-13 Question 3: Which sources produce alternating current? Ch-13 Question 4: Choose the correct option. A rectangular coil of copper wires is rotated in a magnetic field. The direction of the induced current changes once in each Ch-13 Page No 238: Question 1: Name two safety measures commonly used in electric circuits and appliances. Ch-13 Question 2: An electric oven of 2 kW is operated in a domestic electric circuit (220 V) that has a current rating of 5 A. What result do you expect? Explain. Ch-13 Question 3: What precaution should be taken to avoid the overloading of domestic electric circuits? Ch-13 Page No 240: Question 1: Which of the following correctly describes the magnetic field near a long straight wire? (a) The field consists of straight lines perpendicular to the wire Ch-13 Question 2: The phenomenon of electromagnetic induction is- (a) the process of charging a body Ch-13 Question 3: The device used for producing electric current is called a - (a) generator Ch-13 Question 4: The essential difference between an AC generator and a DC generator is that (a) AC generator has an electromagnet while a DC generator has permanent magnet. Ch-13 Question 5: At the time of short circuit, the current in the circuit (a) reduces substantially Ch-13 Question 6: State whether the following statements are true or false. (a) An electric motor converts mechanical energy into electrical energy. Ch-13 Question 7: List three sources of magnetic fields. Ch-13 Page No 241: Question 8: How does a solenoid behave like a magnet? Can you determine the north and south poles of a current-carrying solenoid with the help of a bar magnet? Explain. Ch-13 Question 9: When is the force experienced by a current-carrying conductor placed in a magnetic field largest? Ch-13 Question 10: Imagine that you are sitting in a chamber with your back to one wall. An electron beam, moving horizontally from back wall towards the front wall, Ch-13 Question 11: Draw a labelled diagram of an electric motor. Explain its principle and working. What is the function of a split ring in an electric motor? Ch-13 Question 12: Name some devices in which electric motors are used? Ch-13 Question 13: A coil of insulated copper wire is connected to a galvanometer. What will happen if a bar magnet is (i) pushed into the coil, Ch-13 Question 14: Two circular coils A and B are placed closed to each other. If the current in the coil A is changed, will some current be induced in the coil B? Give reason. Ch-13 Question 15: State the rule to determine the direction of a (i) magnetic field produced around a straight conductor-carrying current, Ch-13 Question 16: Explain the underlying principle and working of an electric generator by drawing a labelled diagram. What is the function of brushes? Ch-13 Question 16: Explain the underlying principle and working of an electric generator by drawing a labelled diagram. What is the function of brushes? Ch-13 Question 17: When does an electric short circuit occur? Ch-13 Question 18: What is the function of an earth wire? Why is it necessary to earth metallic appliances?