a) When S is closed, current flows in the solenoid magnetizing the iron core. This attracts the iron armature closing the contracts. This causes the current to flow in the motor circuit. The motor keeps running continuously
b) Steel would remain permanently magnetized causing current in motor circuit to remain on when the switch is open
johnmulu answered the question on April 19, 2017 at 08:06
- Figure 3 shows a flat spring made of iron clamped horizontally on the bench over a solenoid.(Solved)
Figure 3 shows a flat spring made of iron clamped horizontally on the bench over a solenoid.
When the switch is closed, the spring vibrates. Explain this observation.
Date posted: April 19, 2017. Answers (1)
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Date posted: April 19, 2017. Answers (1)
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Date posted: April 19, 2017. Answers (1)
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i) State the reason why the solenoids are wound in opposite directions around the soft-iron core pieces as shown.
ii) Explain how the speech current from the microphone is converted into sound in the direction receiver.
iii) State and explain the effect of replacing the soft iron core pieces with steel core pieces
Date posted: April 19, 2017. Answers (1)
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Date posted: April 19, 2017. Answers (1)
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In the set up in Fig. 5, the suspended metre rule in equilibrium balanced by the magnet and the weight shown. The iron core is fixed to the bench.
i) State and explain the effect on the metre rule when the switch S, is closed.
ii) What would be the effect of reversing the battery terminals?
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Date posted: April 19, 2017. Answers (1)
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ii) Write an expression to show how the measurements in (i) above are used to obtain the mass of S.
Date posted: April 19, 2017. Answers (1)
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State with a reason whether the lorry is stable or not stable.
Date posted: April 19, 2017. Answers (1)
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Date posted: April 19, 2017. Answers (2)
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Date posted: April 19, 2017. Answers (1)
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Figure 5 shows a uniform bar of length 1.0 m pivoted near one end. The bar is kept in equilibrium by a spring balance as shown.
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Date posted: April 19, 2017. Answers (1)
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Date posted: April 19, 2017. Answers (1)
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Determine the weight of the bar
Date posted: April 19, 2017. Answers (1)
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ii) Explain your answer in (i) above.
Date posted: April 19, 2017. Answers (1)
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Date posted: April 19, 2017. Answers (1)
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Date posted: April 18, 2017. Answers (1)
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Figure 3 shows two identical hollow spheres. Sphere A is completely filled with the liquid while B is partially filled with identical liquid.
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Date posted: April 18, 2017. Answers (1)
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Date posted: April 18, 2017. Answers (1)
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John carried a uniform post of mass 20 kg horizontally on his shoulders as shown in Fig 6. He placed the post on his shoulder such that the centre of gravity of the pole is 1.0 m behind him. He balanced the post by applying a downwards force F at a point 0.5 m on the part of the pole in front of him.
Determine the value of the force F.
Date posted: April 18, 2017. Answers (1)
- In the set up in the Fig. 3, the metre rule is in equilibrium(Solved)
In the set up in the Fig. 3, the metre rule is in equilibrium
Given that the metre rule is uniform, determine its weight.
Date posted: April 18, 2017. Answers (1)