Ans. No , the boundary line of the magnetic field has to be the diameter of the circle , whatever be the velocity of the charged particle . Hence , it will complete a semi – circle .
Ans. True . A charged particle experiences a force at right angles to the velocity and so it moves in a circle with a constant speed . So there is no change in the energy of the particle through a magnetic force acts on it .
Ans. No, We can not be sure that there is no magnetic field because the force will be zero when the direction of motion is along the direction of the field .
Ans. Since the current flowing through the circuit has to pass through the ammeter , it must be connected in series because it is a characteristic property of series connection that the same current passes through all parts of the circuit .
Ans. Because current does not get added or subtracted according to vector algebra , it is not a vector . Heat , current , time , etc. , have a sense but they are not vectors .