# Electromagnetic Induction Multiple Choice

1. May 18, 2010

### yeah:)

Please go to the following link to see the multiple choice questions I am talking about (if I post the image directly into the thread, I shall immediately receive a warning about the size not being suitable for this forum):

http://farm3.static.flickr.com/2731/4475421401_345855f17e_b.jpg

Here are my attempts at answering them, along with my explanations:

1 - C Explanation: by decreasing no. turns you decrease inductance, lowering both self and mutual inductance of the coils and the system.

2 - A Explanation: this is the only choice that would increase deflection; all other choices would decrease the current through the secondary coil.

3 - C Explanation: greater speed = higher frequency= more of the waveform appears on the scope.

4 - D Explanation: this is a turns ratio problem, and d.c. will not be transmitted through a transformer.

5 - E Explanation: faster insertion = more current and opposite direction = reverse current flow direction

6 - D Explanation: rate = power ?????

7 - D (the answer is cut off) Explanation: you want a high voltage and a low current ( current flow causes power loss because wires have resistance)

Please tell me where my answers are wrong, and what the right answers should be (preferably with a small explanation of why that is so!).