Đề thi bằng Tiếng Anh môn Vật lí Lớp 11 - Mã đề: 311 - Năm học 2020-2021 - Sở GD&ĐT Nam Định (Có đáp án)

 NAM DINH DEPARTMENT OF CONTEST OF MATH AND SCIENCE 
 EDUCATION AND TRAINING
 IN ENGLISH
 School year: 2020 - 2021
 OFFICIAL 
 Subject: physics – Grade 11 
 Time allowed: 90 minutes
 CODE: 311
PART 1. (7.0 marks): single-answer multiple-choice
This is a multiple-choice examination with four options A, B, C or D for each question. There is 
only one correct or best answer to each question. Write your answer (A, B, C or D) in the 
correspondingly numbered space on the provided answer sheet. 
Question 1: The electric field at a distance of 10 cm from an isolated point particle with a charge of 1.6 
× 10−9 C is
 A. 144 V/m. B. 1440 V/m. C. 2304 V/m. D. 14400 V/m.
Question 2: What is the equation of Coulomb’s law?
 q .q q .q q .q q .q
A. F k 1 2 . B. F 1 2 . C. F k 1 2 . D. F 1 2 .
 r 2 r 2 r 2 k.r 2
Question 3: What is the unit of electric current?
 A. Volts B. Ohms C. Amperes D. Joules
Question 4: A object dropped from top of a tower falls through 40 m during the last two seconds of its 
fall. The height of the tower (in m) is (Take g = 10 m/s2)
 A. 45 m. B. 50 m. C. 60 m. D. 80 m.
Question 5: Starting from rest, a body slides down a 450 inclined plane in twice the time it takes to slide 
down the same distance in the absence of friction. The coefficient of friction between the body and the 
inclined plane is
 A. 0.33. B. 0.75. C. 0.8. D. 0.25.
Question 6: To make an uncharged object have a negative charge we must
A. add some atoms. B. remove some atoms.
 C. add some electrons. D. remove some electrons.
Question 7: A small object has charge Q. Charge q is removed from it and placed on a second small 
object. The two objects are placed 1 m apart. For the force that each object exerts on the other to be a 
maximum, q should be
 A. Q/2. B. 2Q. C. Q. D. Q/4. 
Question 8: Three unlike resistors are connected in series, each carries currents labeled I1, I2 and I3. 
Which of the following formula expresses the value of the total current IT in the combined system?
 1 1 1 1
 A. B. IT I1 I2 I3
 IT I1 I2 I3
 C. IT 3I1 3I2 3I3 D. IT I1 I2 I3
Question 9: Four 20 Ω resistors are connected in series and the combination is connected to a 20 V emf 
device. The current in any one of the resistors is 
 A. 0.25 A. B. 1.0 A. C. 4.0 A. D. 5.0 A. 
 Page 1-CODE 311 Question 10: The current in the metal is the directional displacement of 
 A. free electrons. B. atoms. C. positive ions. D. negative ions.
Question 11: Which of following quantities is not a vector?
 A. Displacement. B. Weight. C. Acceleration. D. Mass.
Question 12: 273 cm3 of an ideal gas is at 00 C. It is heated at constant pressure to 100 C. It will now 
occupy
 A. 263 cm3. B. 278 cm3. C. 283 cm3. D. 293 cm3.
Question 13: Two small charged objects attract each other with a force F when separated by a distance d. 
If the charge on each object is reduced to one-fourth of its original value and the distance between them 
is reduced to d/2 the force becomes
 A. F/2. B. F/4. C. F/8. D. F/16. 
Question 14: Two particles, X and Y, are 4 m apart. X has a charge of 2Q and Y has a charge of Q. The 
force of X on Y has 
 A. twice the magnitude of the force of Y on X. B. half the magnitude of the force of Y on X. 
 C. four times the magnitude of the force of Y on X. D. the same magnitude as the force of Y on X.
Question 15: A current of 0,5 A exists in a 60 ohm lamp. The applied potential difference is 
 A. 15 V. B. 30 V. C. 60 V. D. 120 V.
Question 16: If the potential difference across a resistor is doubled,
 A. only the current is doubled. B. only the current is halved. 
 C. only the resistance is doubled. D. both the current and resistance are doubled.
Question 17: During an electrolysis of molten sodium chloride (Nacl), a 8A current is passed through 
electrodes for 2 hours. The atomic weight of sodium is 23. Calculate the mass of sodium that is 
produced during this time
 A. 13.72 mg. B. 13.72 g. C. 8.31 mg. D. 23 g.
Question 18: A block of mass 3 kg is suspended by a massless rope of 
length 2 m from the ceiling. A force of 10 N is applied in the horizontal 
direction at the midpoint P of the rope, as shown in the figure. The angle 
made by the rope with the vertical in equilibrium is 10 N
 A. 400. B. 300. C. 450. D. 600.
Question 19: Two forces are applied to a 2kg crate; one is 6 N to the north and the other is 8 N to the 
west. The magnitude of the acceleration of crate is
 A. 3 m/s2. B. 4 m/s2. C. 5 m/s2. D. 7 m/s2.
Question 20: Two particles have charges Q and −Q (equal magnitude and opposite sign). For a net force 
of zero to be exerted on a third charge it must be placed
 A. midway between Q and –Q. 
 B. on the perpendicular bisector of the line joining Q and −Q, but not on that line itself .
 C. on the line joining Q and −Q, to the side of Q opposite –Q. 
 D. at none of these places (there is no place).
Question 21: A particle with charge 3.2 ×10 −6 C is placed at the origin. An identical particle, with the 
same charge, is placed 2 m from the origin on the x axis, and a third identical particle, with the same 
charge, is placed 2 m from the origin on the y axis. The magnitude of the force on the particle at the 
origin is
 A. 2.3 × 10−2 N. B. 3.3 × 10−2 N. C. 4.6 × 10−2 N. D. 6.6 × 10−2 N.
Question 22: A car battery is rated at 80 A.h. An ampere-hour is a unit of
 A. power. B. energy. C. current. D. charge.
 Page 2-CODE 311 Question 23: Resistances of 2 Ω, 4 Ω, and 6 Ω and a 24V emf device are all in series. The potential 
difference across the 2 Ω resistor is 
 A. 4 V. B. 8 V. C. 12 V. D. 24 V.
Question 24: A 2 kg object is moving at 3 m/s. A 4 N force is applied in the direction of motion and then 
removed after the object has traveled an additional 5 m. The work done by this force is
 A. 12 J. B. 15 J. C. 20 J. D. 40 J. 
Question 25: A battery is connected across a series combination of two identical resistors. If the 
potential difference across the terminals is V and the current in the battery is i, then
A. the potential difference across each resistor is V and the current in each resistor is i. 
B. the potential difference across each resistor is V /2 and the current in each resistor is i/2. 
C. the potential difference across each resistor is V and the current in each resistor is i/2. 
D. the potential difference across each resistor is V /2 and the current in each resistor is i.
Question 26: Resistor 1 has twice the resistance of resistor 2. The two are connected in series and a 
potential difference is maintained across the combination. The rate of thermal energy generation in 
resistor 2 is 
 A. the same as that in1. B. twice that in 1. C. half that in 1. D. four times that in 1.
Question 27: Two bulbs of 500 W and 200 W are manufactured to operate on 220 V line. The ratio of 
heat produced in 500 W and 200 W, in two cases, when firstly they are connected in series and secondly 
in parallel will be
 A. 2.5 : 2.5. B. 2.5 : 0.4. C. 0.4 : 2.5. D. 0.4 : 0.4.
Question 28: A currents source drives a current in a coil of resistance R1 for a time t. The same source 
drives current in another coil of resistance R2 for same time t. If heat generated is same, internal 
resistance of source is 
 R1.R2 R1 R2
 A. B. R1 R2 C. R1.R2 D. 
 R1 R2 R1.R2
Question 29: Which of the following four quantities is not an expression for energy? Here m is a mass, g 
is the acceleration due to gravity, h and d are distances, F is a force, v is a speed, a is an acceleration.
 A. ma. B. mgh. C. mv2/2. D. Fd. 
Question 30: Choose the correct statement concerning electric field lines
 A. field lines may cross. 
 B. field lines are close together where the field is large. 
 C. field lines point away from a negatively charged particle. 
 D. a charged point particle released from rest moves along a field line. 
Question 31: A nichrome wire is 1 m long and 1 × 10−6 m2 in cross-sectional area. When connected to a 
potential difference of 2 V, a current of 4 A exists in the wire. The resistivity of this nichrome is: 
A. 10−7 Ω.m. B. 2 × 10−7 Ω.m. C. 4 × 10−7 Ω.m. D. 5 × 10−7 Ω.m.
Question 32: An electron traveling north enters a region where the electric field is uniform and points 
south. The electron
 A. speeds up. B. slows down. 
 C. veers east. D. continues with the same speed in the same direction.
Question 33: Particle 1 with a charge of 1.6 × 10−6 C and a mass of 20 g moves uniformly with a speed 
of 3 m/s in a circular orbit around a stationary particle 2 with a charge of −1.6×10 −6 C. Which of the 
following statement is incorrect? 
A. The radius of the orbit is 0.128 m. B. Frequency of the particle 1 is 3.73 Hz. 
C. Period of the particle 1 is 0.27 s. D. The magnitude of the force on particle 1is 0,47 N. 
 Question 34: An certain resistor dissipates 0.5 W when connected to a 3 V potential difference. When 
connected to a 1 V potential difference, this resistor will dissipate: 
 A. 0.5W. B. 0.167W. C. 0.056W. D. 1.5W. 
 Page 3-CODE 311 Question 35: In the circuit shown, internal resistance of source is zero. The 
resistance r is a variable resistance. If for r = kR. The heat generation in r is E
maximum, then the value of k is
 R
 A. 1. B. 1/2. C. 2. D. 1/4. R
PART 2 (3,0 marks) Problem-solving r
Problem 1. A +40 C charge and a +160 C charge are set 9.0 m apart. An unknown positive charge is 
placed on a line joining the first two charges and it is allowed to move until it comes to rest between the 
two charges. At what distance measured from the 160 C charge will the unknown charge come to rest?
Problem 2.
 a I
Calculate the terminal voltage for a battery with an internal resistance 
of r = 0.9  and an emf of  =8.5 V when the battery is connected in 
series with:
 (a) R= 81.0- resistor, R
 (b) R= 810- resistor. ε
 r
 b
Problem 3.
Find the current through each resistor in the multiloop circuit above. 
 a
 R1= 8Ω R2= 12Ω R3= 20Ω
 b
 ε1= 6 V ε2= 3 V
 ---THE END---
Student’s full name............................... Student’s ID...............................
First observer’s name and signature 
Second observer’s name and signature 
 Page 4-CODE 311