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www.GOALias.blogspot.com13. In the circuit shown in Fig. 14.25A B CFig. 14.25(i)(ii)Would any of the bulb glow when the switch is in the ‘OFF’position?What will be the order in which the bulbs A, B and C will glowwhen the switch is moved to the ‘ON’ position?Extended Learning — Activities and Projects1. Set up the circuit shown in Fig. 14.17 again. Move the key to ‘ON’position and watch carefully in which direction the compass needlegets deflected. Switch ‘OFF’ the current. Now keeping rest of the circuitintact, reverse the connections at the terminal of the cell. Again switch‘on’ the current. Note the direction in which the needle gets deflected.Think of an explanation.2. Make four electromagnets with 20, 40, 60 and 80 turns. Connect themone by one to a battery of 2 cells. Bring the electromagnet near a box ofpins. Count the number of pins attracted by it. Compare the strengthsof the electromagnets.Paheli and Boojho saw a magic trick sometime back. The magician placedan iron box on a stand. He then called Boojho and asked him to lift thebox. Boojho could easily lift the box. Now the magician made a show ofmoving his stick around the box while muttering some thing. He againasked Boojho to lift the box. This time Boojho could not even move it. Themagician again muttered some thing and now Boojho could lift the box.The audience, including Paheli and Boojho, were very impressed withthe show and felt that the magician had some supernatural powers.However, after reading this chapter Paheli is wondering if the trick wasindeed some magic or some science was involved? Can you guess whatscience might be involved?172SCIENCE