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Discussions on certain questions.

  1. Oct 20, 2013 #1
    Q. No. 1. If Watt measures power, what does volt measure?

    A. Electrical current

    B. Energy

    C. Electromagnetic force

    D. Electrical resistance


    Q.No. 2. Which of the following statements is false?

    A. A body can have zero velocity and still be accelerated

    B. A body can have a constant velocity and a varying speed

    C. A body can have a constant speed and a varying velocity

    D. The direction of the velocity of a body can change when
    its acceleration is constant.

    These questions were asked in an exam. The examiner says if you have any objection to these questions, you are allowed to raise it.
     
    Last edited: Oct 20, 2013
  2. jcsd
  3. Oct 20, 2013 #2
    None of the above! :confused:
     
  4. Oct 20, 2013 #3
    Should I assume electromagnetic force is a typing error for electromotive force, and choose C.
    Or should i say potential difference is work done on a unit charge in moving it from one point to another. This work is stored as potential energy. So, this leads to choice B.
    Or should i raise my objection to the examiner that the question is wrong?
     
  5. Oct 20, 2013 #4
    in the second question B is false because speed is the magnitude of velocity , and as the magnitude changes , the vector changes
    in D , A = dV/dt
    or the change in velocity over the change in time
    if the change in time is constant , but velocity is changing then surely acceleration will change
    velocity is a vector , it depends on the magnitude which is the speed , and the direction of that speed , if you change the direction , the velocity vector changes , thus leading to a change in acceleration ,
    so both B and D are incorrect in my opinion , if i am wrong , i hope someone would correct me
     
  6. Oct 20, 2013 #5
    In Q no. 1, B is the false statement. The magnitude of velocity is speed. if speed varies obviously, the velocity has to vary.
     
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