Question

True/False

1) A wire carrying current due east in a magnetic field is deflected due north. The magnetic field must have a component that points into the ground

2) The self-inductance of a solenoid depends on the geometry of the solenoid and is independent of the current flowing through it

3) A horizontal bar that is oriented east to west is pulled vertically upward through a magnetic field that points due north. The east end of the bar is at a higher potential than the west end

4) An AC source of fixed rms voltage is connected to an inductor. When the frequency of the source increases, the inductive reactance decreases

5) An AC source of fixed rms voltage is connected to a capacitor. When the frequency of the source decreases, the rms current flowing through the capacitor increases

6) When the amplitude of the electric field of an EM wave traveling in a vacuum is doubled, the intensity is always quadrupled

7) For an EM wave traveling in a vacuum, the energy carried in its electric field is always larger than the energy carried in its magnetic field

8) The image formed from a spherical mirror can be determined from any two rays that originate from the same point on the object

9) The images formed from a convex mirror are always virtual, upright, and larger than the objects that form them

Answer 1

1. True ,  as form the Flemings right hand rule here we have the velocity in the north direction and current in east then there must be magnetic field pointing towards ground as stated by the rule.

2. True, as form the formula of self inductance we can see that it is entirely depends on the geometry of the solenoid not on the current flowing through it.

3. False , as from the right hand rule here the positive charges stars accumulating at the west so that west will be at the higher potential not the east.

4. False, as the inductive reaction is given by

Xl = wL = 2piefL

Here inductive reactance and frequency are directly proportional so as frequency increases inductive reactance increases.

5. False ,Current in a capacitive circuit is given as

I = jwCV = j2piefCV

So here as we increase the frequency our current will also be increased .

6. True , as intensity is proportional to the square of the amplitude, So if the amplitude of a sound is doubled, its intensity is quadrupled

7. True, As we know that energy carried by em wave is related as B = E/c

Where c is the speed light so that here B will always be lesser than E as c is greater than one

8. True , minimum two rays of object is required to get its image in spherical mirrors

9. False, as image formed by convex mirror is always virtual, erected and diminished .