Physics Final exam 1
If the length and diameter of a wire of circular cross section are both tripled, the resistance will be
D) 1/3 of what it originally was
When a dielectric material is introduced between the plates of a parallel-plate capacitor and completely fills the space, the capacitance increases by a factor of 4. What is the dielectric constant of the material that was introduced?
D) 4
2 stationary point charges q1 and q2 are shown in the figure along with a sketch of some field lines representing the electric field produced by them. what can you deduce form the sketch?
D) q1 is negative and q2 is positive; the magnitude of q1 is less than the magnitude of q2
Four resistors having resistances of 20 ohm, 40 ohm, 60 ohm, and 80 ohm are connected in series across an ideal dc voltage source. If the current through this circuit is .50 A what is the voltage of the voltage source?
E) 100v
2 charges of opposite sign and equal magnitude q=0.82 C are held 2 m apart as shown by the figure. Determine the electric potential at the point P.
E) zero volts
2 identical bulbs in series will not have the same brightness T/F
F
2 protons are released from rest, with only the electrostatic force acting, their acceleration will keep increasing T/F
F
Doubling the capacitance of a capacitor that is holding a constant charge causes the energy stored in that capacitor to double T/F
F
For AC current the RMS current, IRMS is the maximum or peak current T/F
F
If the resistance in a constant voltage circuit is doubled, the power dissipated by that circuit will increase by a factor of 2 T/F
F
The length of a certain wire is kept the same while it's radius is doubled. The resistance of this wire does not change T/F
F
The strength of the electric field between 2 oppositely charged parallel plates is not uniform from the positive plate to the negative plate T/F
F
the electron volt eV is a unit of power T/F
F
4 point charges of equal magnitude but with varying signs are arranged on three of the corners and at the center of the square of side d as shown in the figure. Which one of the arrows shown represents the net force acting on the center charge
A
Which one of the arrows shown in the figure best represents the direction of the electric field between the two uniformly charged metal plates?
A
A dielectric material such as paper is inserted between the plates of a capacitor as the capacitor holds a fixed charge on its plates. The electric field between the plates as the dielectric is inserted will become weaker. T/F
T
A hydrogen nucleus, which has a charge +e, is situated to the left of a carbon nucleus, which has a charge +6e. is it true that the electrical force experienced by the hydrogen nucleus is to the left, and the magnitude is equal to the force of exerted on the carbon nucleus. T/F
T
Electrically neutral objects cannot exert an electrical force on eachother T/F
T
Suppose you have 2 capacitors and want to use them to store the maximum amount of energy by connecting them across a voltage source. Should you connect them in parallel across the source? T/F
T
The amount of current in a circuit depends jointly on the battery's emf and the resistance of the circuit attached to the battery T/F
T
The fundamental charge (e) is the magnitude of the charge of an electron or proton e= 1.60x10^-19 C T/F
T
The resistivity of a material increases as the temperature goes up. T/F
T
A charge of 12C passes through an electroplating apparatus in 2 min. What is the average current in the apparatus?
A) o.10 amps
Four unequal resistors are connected in a parallel with each other. Which one of the following statements is correct about this combination? A) the equivalent resistance is less than that of the smallest resistor B) the equivalent resistance is equal to the average of the four resistances C) the equivalent resistance is midway between the largest and smallest resistance D) the equivalent resistance is more than the largest resistance E) none of the above
A- the equivalent resistance is less than that of the smallest resistor
if the maximum voltage of an AC signal is 8.0V, what is the rms value of this voltage?
B 5.7 volts
Kirchoff's junction rule is a statement of
B) the law of conservation of charge
the plates of a parallel-plate capacitor are maintained with constant voltage by a battery as they are pulled apart. what happens to the strength of the electric field between the plates during this process?
B- it decreases
In a region where the electric field is uniform and points in the positive x direction, the electric potential is -2000 V at x=8m and is 400+ V at x=2m. what is the magnitude of the electric field?
C) 400 V/m