Q3 - General Physics - PDF

1.​ If two resistors with resistances of 10 D. The total power dissipated in a Ω and 20 Ω are connected in series circuit is equal to the product of the to a 30 V battery, and then total current and total voltage. connected in parallel to the same...

1.​ If two resistors with resistances of 10 D. The total power dissipated in a Ω and 20 Ω are connected in series circuit is equal to the product of the to a 30 V battery, and then total current and total voltage. connected in parallel to the same 4.​ Which of the following best battery, which of the following describes charging by induction? statements is true about the total current in the circuit? A. Transferring charge by directly touching another object A. The total current in the series B. Charging an object by rubbing it circuit will be greater than in the with another material parallel circuit. C. Rearranging the charges in an B. The total current in the series object without direct contact circuit will be the same as in the D. Destroying charges by bringing parallel circuit. an object near a neutral body C. The total current in the parallel circuit will be greater than in the 5.​ A wire's resistance is 8 Ω. If the series circuit. length of the wire is doubled while D. The total current in both circuits the cross-sectional area is halved, will be zero. how will the new resistance compare to the original resistance? 2.​ When an object becomes charged by rubbing, what causes the charge A. The new resistance will be 16 Ω. transfer to occur? B. The new resistance will be 4 Ω. C. The new resistance will be 32 A. Protons moving between objects Ω. B. Neutrons moving between objects D. The new resistance will be 64 Ω. C. Electrons transferring from one object to another 6.​ What is the key difference between D. The objects sharing their charges charging by rubbing and charging by equally induction? 3.​ Which of the following best A. Rubbing involves contact, describes Kirchhoff's Current Law while induction does not require (KCL)? direct contact B. Induction transfers protons while A. The sum of the potential rubbing transfers neutrons differences around any closed loop C. Rubbing creates charges, while is zero. induction destroys charges B. The total current entering a D. Induction involves rubbing objects junction is equal to the total together to generate heat current leaving the junction. C. The total resistance in a parallel 7.​ If the length of a wire is halved and circuit is equal to the sum of the its cross-sectional area is doubled, individual resistances. how will the resistance of the wire  change according to the relationship correct approach to calculate the R=ρ L/A? electric field at a point midway between them? A. The resistance will remain the same. A. Use Coulomb’s law to calculate B. The resistance will double. the field due to each charge and C. The resistance will be halved. then add the magnitudes of the D. The resistance will be reduced by fields directly. a factor of 4. B. Use Coulomb’s law to find the field vectors due to each charge 8.​ What principle calculates the net and add them using vector electric field at a point due to addition. multiple charges? C. Find the net charge and use Coulomb’s law to calculate the total A. Coulomb's law and the principle field. of charge conservation D. Ignore the charges since the point B. The superposition principle, is equidistant from both. summing vector contributions from each charge 11.​If the length of a wire is doubled and C. Gauss's law applied to point its crosssectional area is halved, charges how will the resistance of the wire D. Subtracting the weaker charge change according to the formula for field from the stronger one resistance R=ρ L/A, where ρ is the resistivity, L is the length, A is the 9.​ According to the formula R=ρ L/A, cross-sectional area? which of the following statements is correct regarding the relationship A. The resistance will remain the between resistance, length, and same. crosssectional area of a wire? B. The resistance will double. C. The resistance will quadruple. A. The resistance of a wire D. The resistance will increase by a increases as its length decreases. factor of 4. B. The resistance of a wire decreases as its crosssectional 12.​A charge of an atom, q=+4 C is area increases. placed 6 m apart along a straight C. The resistance of a wire line. What is the magnitude of the increases as its crosssectional area net electric field? increases. D. The resistance of a wire is A. 9.99 x 108 N/C independent of its length and B. 9.0 x 108 N/C cross-sectional area. C. 9 x 108 N/C D. 10 x 108 N/C 10.​Two charges, q1=+2 C and q2=−3 C are placed 4 m apart. What is the 13.​A light bulb has a resistance of 12 Ω. 17.​Which of the following best When connected to a 24 V power describes the relationship between supply, what is the current flowing current, voltage, and resistance in through the light bulb according to Ohmic materials, according to Ohm's Ohm's law? law? A. 1 A A. The current is directly B. 2 A proportional to the voltage and C. 12 A inversely proportional to the D. 24 A resistance. B. The current is inversely 14.​Find the electrostatic force between proportional to both the voltage and charges of +5.0 C and +3.0 C the resistance. separated by a distance of 75 m in a C. The voltage is directly vacuum. proportional to the resistance and inversely proportional to the current. A. 3.2 x 107 N D. The voltage is directly B. 2.7 x 107 N proportional to the current and C. 1.8 x 107 N inversely proportional to the D. 2.4 x 107 N resistance. 15.​In an electrical circuit with a resistor 18.​You are designing an electronic made of Ohmic material, the device with a sensor that operates resistance is 10 Ω, and the voltage based on electric fields. Two small across the resistor is 20 V. Using charged objects, q1=+5 μC, and Ohm's law, what is the current q2=−3 μC, are placed 4 m apart on a flowing through the resistor? straight line to create an electric field for the sensor. The sensor is located A. 0.5 A at a point, which is 2 m from q1 and B. 2 A 2 m from q2. What is the net electric C. 20 A field experienced by the sensor at D. 200 A this point? 16.​Two charges of +8.0 C and -6.0 C A) 5×104 N/C attract each other with a force of 3.0 B) 4 × 104 N/C x 103 N in a vacuum. What is the C) 1.8×104 N/C distance between the charges? D) 2 × 104 N/C A. 4.3 x 107 m 19.​A current of 0.25 A flows through a B. 1.6 x 107 m conductor for 2 hours, and the same C. 1.2 x 107 m current flows through another D. 3.5 x x 107 m conductor for 5 hours. Which conductor experiences a greater total charge transfer?  for 30 minutes transfers more A. The conductor with 0.25 A for 2 charge. hours transfers more charge. C. Both situations transfer the same B. The conductor with 0.25 A for 5 charge. hours transfers more charge. D. The situation with 4 A current for C. Both conductors transfer the 10 minutes transfers less charge. same amount of charge. D. The conductor with 0.25 A for 2 22.​Two point charges, +4 μC and −6 μC hours transfers at no charge. are placed 8 m apart. A third charge, +2 μC is located 3 m away from q1 20.​A charge q0=+1 μC is placed at the and 5 m away from q2. What can be origin of a coordinate system. Two said about the direction of the net other charges, q1=+2 μC and force on q3 ? q2=−3 μC are located at points (2 m, 0) and (0,3 m), respectively. Which A) The net force on q3 points toward of the following steps is incorrect in q1. determining the net force on q0 due B) The net force on q3 points toward to q1 and q2 ? q2. C) The net force on q3 points A) Calculate the force due to q1 on somewhere between q1 and q2 , q0 using Coulomb's law. depending on their relative force B) Calculate the force due to q2 on magnitudes. q0 using Coulomb's law. D) The net force on q3 is zero C) Add the magnitudes of the because the charges cancel each forces due to q1 and q2 directly other. without considering their directions. 23.​A battery is connected to a resistor D) Use vector addition (Pythagorean and a current of 0.5 A flows for 20 theorem) to calculate the net force minutes. After 10 minutes, the on q0 by combining the x and y current is increased to 1.0 A. What is components of the forces. the total charge transferred during these 20 minutes? 21.​A current of 4 A flows through a conductor for 10 minutes. If the A) 10 C conductor is replaced and the B) 12 C current is reduced to 2 A, but the C) 15 C time is increased to 30 minutes, D) 20 C which situation results in a greater total charge transferred? 24.​When two charges exert forces simultaneously on a third charge, the A. The situation with 4 A current for total force acting on that charge is 10 minutes transfers more charge. the vector sum of the forces that the B. The situation with 2 A current two charges would exert individually.  This principle is known as the B. The total charge will be halved. _____. C. The total charge will double. D. The total charge will be A. interference of charge quadrupled. B. Coulomb’s principle C. superposition of force 28.​An air purifier uses an electric field D. superposition of electric field to trap dust particles by charging them as they pass through a region 25.​A current of 2 A flows through a with a uniform electric field. If the conductor for 3 minutes. If the dust particles are modeled as tiny current is maintained for an charged spheres and a Gaussian additional 2 minutes, what will surface is imagined around one of happen to the total charge these particles, which of the transferred during these 5 minutes? following statements is correct about the electric flux through the A. The total charge transferred will Gaussian surface? increase to 10 C. B. The total charge transferred A. The electric flux depends on the will increase to 12 electric field strength generated by C. The total charge transferred will the air purifier. decrease to 8 C. B. The electric flux depends only D. The total charge transferred will on the charge of the dust particle remain at 6 C. enclosed by the Gaussian surface. 26.​Two charged objects attract each C. The electric flux depends on the other with a certain force. If the radius of the Gaussian surface charges on both objects are doubled around the dust particle. with no change in separation, what D. The electric flux is zero because will happen to the force between the charge is small. them? 29.​If the current in a circuit is constant and flows for a longer period, what A. quadruples happens to the total charge B. doubles transferred according to the equation C. halves Q=I × t? D. increases A. The total charge increases 27.​If the current in a circuit is doubled because the charge is directly while keeping the time constant, proportional to time. what will happen to the total charge B. The total charge decreases transferred according to the equation because the charge is inversely Q= I × t? proportional to time. C. The total charge remains the A. The total charge will remain the same regardless of the time. same.  D. The total charge increases statements is true about the electric because the charge is inversely flux through the surface? proportional to time. A. The electric flux is maximum 30.​In photocopiers, a uniform electric when the surface is oriented field is used to distribute toner parallel to the electric field. particles on a charged drum. If a B. The electric flux is zero when the toner particle carries a charge surface is perpendicular to the q=−5 μC, which of the following electric field. statements best describes the C. The electric flux is the same for electric flux through a Gaussian any orientation of the surface. surface surrounding the toner D. The electric flux is minimal when particle? the surface is oriented parallel to the electric field A. The electric flux depends on the total electric field created by the 33.​What does the equation Q=I × t drum and the toner particle. represent in terms of electric B. The electric flux is negative current? because the toner particle has a negative charge. A. The total amount of charge C. The electric flux depends on the passing through a conductor in a size of the Gaussian surface around given time. the toner particle. B. The energy required to move a D. The electric flux is positive charge through a conductor. because the drum creates a uniform C. The force experienced by a electric field charge in a conductor. D. The voltage required to move a 31.​If the current in a circuit is 3 A and it certain amount of charge through a flows for 5 seconds, what is the total conductor. charge transferred during this time according to the equation Q=I × t? 34.​A spherical surface of r=5 m surrounds a point charge q=+2 μC. If A) 15 C the radius of the spherical surface is B) 8 C doubled to r=10, how does the C) 3 C electric flux through the surface D) 5 C change? 32.​An electric field of 6 N/C on a flat A. The electric flux doubles because surface with an area of 4 m2 is the surface area increases. placed in the field. The surface is B. The electric flux is halved oriented at different angles for the because the radius increases. electric field, and the electric flux C. The electric flux remains the through the surface is calculated for same because it depends only on each angle. Which of the following the enclosed charge.  D. The electric flux increases by a 4 is inserted while the capacitor is factor of four because the radius disconnected from the power supply. increases. What will happen to the charge, capacitance, and voltage across the 35.​A capacitor with a capacitance 5 μF plates? is charged to a voltage of 10 V, storing a charge of 50 µC. Suppose A. The capacitance increases to the capacitor is connected to a 40 µF, the charge remains the battery that maintains a constant same at 60 µC, and the voltage voltage of 10 V, and a dielectric with decreases to 1.5 V. a dielectric constant of 2 is inserted. B. The capacitance increases to 40 What will happen to the charge, µF, the charge increases to 240 µC, capacitance, and voltage across the and the voltage remains the same at plates? 6 V. C. The capacitance increases to 40 A. The capacitance increases to 10 µF, the charge remains the same at µF, the charge remains the same, 60 µC, and the voltage remains the and the voltage decreases to 5 V. same at 6 V. B. The capacitance increases to D. The capacitance remains at 10 10 µF, the charge increases to 100 µF, the charge remains the same at µC, and the voltage remains at 10 60 µC, and the voltage increases to V. 24 V. C. The capacitance remains the same, the charge remains at 50 µC, 38.​Which of the following correctly and the voltage remains at 10 V. describes how the strength of the D. The capacitance increases to 10 electric field changes when the µF, the charge remains at 50 µC, distance from a point charge is and the voltage remains at 10 V. doubled? 36.​Which of the following factors does A. The electric field strength not affect the strength of the electric doubles. field created by a point charge? B. The electric field strength is halved. A. The magnitude of the charge. C. The electric field strength is B. The distance from the charge. reduced by a factor of four. C. The presence of other charges D. The electric field strength remains nearby. unchanged. D. The medium (material) surrounding the charge 39.​Which of the following is a correct statement about the direction of the 37.​A capacitor with a capacitance of 10 electric field created by a positive µF is charged to 6 V, storing a point charge? charge of 60 µC. Suppose a dielectric with a dielectric constant of  A. The electric field points radially inward toward the charge. 42.​In a camera’s flash unit, capacitors B. The electric field points radially are used to store energy. Why are outward from the charge. capacitors the preferred choice in C. The electric field is tangent to the this application? surface of a sphere surrounding the charge. A. Capacitors can release the D. The electric field is parallel to the stored energy quickly to generate line connecting two positive charges. a high-intensity flash. B. Capacitors allow energy to be 40.​What happens when a dielectric stored for a long time, ensuring the material is inserted between the flash is ready whenever needed. plates of a charged capacitor? C. Capacitors regulate power consumption to reduce energy A. The capacitance increases, the usage. charge on the plates decreases, and D. Capacitors amplify the energy to the electric field remains the same. create a stronger flash. B. The capacitance increases, the charge on the plates remains the 43.​Which of the following best same, and the electric field describes the electric potential at a decreases. point due to a positive point charge? C. The capacitance decreases, the charge on the plates remains the A. The electric potential is always same, and the electric field negative at all points. increases. B. The electric potential D. The capacitance decreases, the decreases as the distance from charge on the plates increases, and the charge increases. the electric field decreases. C. The electric potential increases as the distance from the charge 41.​Which of the following best increases. describes the nature of the electric D. The electric potential is constant field between two parallel plates and independent of the distance connected to a battery? from the charge. A. The electric field is uniform and 44.​Why are capacitors important in points from the positive plate to signal processing applications, such the negative plate. as in audio systems or radio B. The electric field is radial and receivers? points away from the positive plate. C. The electric field is non-uniform A. They prevent the loss of signal and points from the negative plate to strength by amplifying weak signals. the positive plate. B. They filter out unwanted D. The electric field is zero between frequencies, allowing only the the plates. desired signal to pass.  C. They act as resistors to control A. To control the rate at which the the current flow in the circuit. circuit charges and discharges, D. They store energy and release it determining the timing cycle. to keep the signal at a constant B. To reduce the power consumption level. of the circuit. C. To store magnetic energy for 45.​What is the electric potential at a short bursts of power. point halfway between two equal D. To increase the voltage of the and opposite charges +Q and −Q, circuit over time. separated by a distance? 49.​If the distance between two charges A. The electric potential is zero. is doubled, how does the electric B. The electric potential is positive. potential energy of the system C. The electric potential is negative. change? D. The electric potential is infinite. A. The electric potential energy is 46.​How do capacitors contribute to the doubled. functioning of a filtering circuit in B. The electric potential energy is electronics? halved. C. The electric potential energy is A. Capacitors allow high-frequency reduced by a factor of four. signals to pass through while D. The electric potential energy blocking low-frequency signals. remains unchanged. B. Capacitors store high-frequency signals and prevent them from 50.​Why are capacitors used in power entering the circuit. supply circuits in electronic devices? C. Capacitors smooth out fluctuations in voltage by storing A. To store and release electrical and releasing charge. energy to smooth out fluctuations D. Capacitors store power and in voltage. release it only when the circuit is B. To increase the total resistance in turned off. the circuit. C. To convert AC into DC. 47.​ A D. To store and discharge magnetic energy. 48.​Why are capacitors used in timing circuits, such as those in oscillators or clocks?