Physics MCQ series - 05

Phy-Q,

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41:  For a parallel-plate capacitor with plate area "A" and plate separation "d", the capacitance is proportional to which of the following?

w) A divided by d squared

x) A times d

y) A divided by d

z) d divided by A

ANSWER:   Y -- A DIVIDED BY D

42:  A constant potential difference is applied across the plates of a parallel-plate capacitor.  Neglecting any edge effects, the electric field inside the capacitor is:

w) constant

x) varying as one over r squared

y) decreasing as one moves from the positive to the negative plate 

z) zero

ANSWER:   W -- CONSTANT

43:  A 10 farad capacitor is used in a circuit.  The voltage difference between the plates of the capacitor is 20 volts.  What is the magnitude of the charge on each of the capacitor's plates?

ANSWER:  200 COULOMBS

44:  A circuit which employs a DIRECT CURRENT source has a branch which contains a capacitor.  After the circuit has reached a steady state, what is the magnitude of the current in the circuit branch which contains the capacitor?

ANSWER:  THE CURRENT IS ZEROScience Bowl PHYSICS

45:  A charged particle is moving in a UNIFORM magnetic field.  If the direction of motion of the charged particle is parallel to the magnetic field, describe the shape of the charged particle's path.

ANSWER:   STRAIGHT LINE

46:  An infinitely long wire carries a current of three amps. The magnetic field outside the wire:

w) points radially away from the wire

x) points radially inward

y) circles the wire

z) is zero.

ANSWER: Y -- CIRCLES THE WIRE

47:  A copper rod which is 1 centimeter in diameter carries a current of 5 amps.  The current is istributed uniformly throughout the rod.  The magnetic field half way between the axis of the rod and its outside edge is:

w) zero.

x) pointing radially outward

y) pointing radially inward

z) circles the axis of the rod

ANSWER:   Z -- CIRCLES THE AXIS OF THE ROD

48:  Iron is what type of magnetic material?  Is it:

w)  diamagnetic

x)  paramagnetic

y)  ferromagnetic

z)  non-magnetic

ANSWER:   Y -- FERROMAGNETIC

49:  The focal length of a concave mirror is 2 meters.  An object is positioned 8 meters in front of the mirror.  Where is the image of this object formed?

ANSWER:   8/3 METER   or   2.66 METERS IN FRONT OF THE MIRROR Science Bowl PHYSICS

50:  A converging thin lens has a focal length of 27 centimeters.  An object is placed 9 centimeters from the lens.  Where is the image of this object formed?

ANSWER:   -13.5 CENTIMETERS  or  13.5 CENTIMETERS ON THE OBJECT SIDE

OF THE LENS