a và c e không xác định được

... frequency f = 50Hz The capacitance C is adjusted to be 10μF a) Calculate the circuit impedance b) Calculate the rms value of current c) Calculate the capacitance so as to get a maximum value ... 50Hz between the two terminals Calculate the capacitive impedance and the current intensity A circuit has a capacitor, capacitance C = 20μF The resistance is negligible There is an alternating ... Dec 2001 Page 21 Chapter II – MECHANICAL WAVE A COUSTICS §8 WAVE IN MECHANICS Natural mechanical waves When we throw a rock into a still water surface, we can observe a number of circular water...

Ngày tải lên: 25/10/2014, 03:00

... N(placel1) + to + N(placel2)? Its about + distace Hỏi đờng đến nơi trả lời : Could you tell me how to get / go to + N (place) , plase? Could you show me the way to + (place) ? - Go straight ahead ... + be + The +adj est * Tính từ dài : S + be + the most + adj * Xem số trờng hợp đ c biệt : Good Better ; C u c m thán : What + (a/ an) + adj +N ! = how + adj + S + Be ! C u đề nghị : Let +Vinf ... + Time Year Week Tomorrow, tonigh Some important structure So sánh c tính từ : a So sánh : *Tính từ ngắn :S1 + be(chia ) + adj er + than + S2 *Tính từ dài : S1 + be + more + adj + than + S2...

Ngày tải lên: 25/09/2013, 20:10

... lng kớnh c g c lch cc tiu Khi ú A ch c thờm tia mu lc c g c lch cc tiu B tia mu cng c g c lch cc tiu C ba tia c n li lú lng kớnh khụng c tia no c g c lch cc tiu D ba tia , vng v lc khụng ... c u tr li sai Hai nguyờn t kh c cú c im quang ph vch phỏt x kh c v : A sỏng t i gia c c vch quang ph B b rng c c vch quang ph C s lng c c vch quang ph D.mu sc c c vch mu v v trớ c c vch mu C u ... v giao thoa ỏnh sỏng, c c khe S1,S2 c chiu bi ỏnh ỏng n sc.Khong c ch gia hai khe l a = 0,5mm Khong c ch gia mt phng cha hai khe v mn quan sỏt l D = 2m Bit khong c ch gia võn sỏng liờn tip cnh...

Ngày tải lên: 13/03/2015, 16:34

... nhìn bị cong Định ngh a: Hiện tượng kh c xạ ánh sáng xảy tia sáng (đơn s c) truyền xiên g c tới mặt phân c ch hai môi trường suốt c chiết suất kh c Chú thích: SI tia tới IK tia kh c xạ i g c tới, ... kh c xạ Trong hình vẽ i1 : g c tới i2 : g c ló, g c kh c xạ lần kh c xạ thứ hai r1 : g c kh c xạ tia sáng lần kh c xạ thứ r2 : g c tới tia sáng lần kh c xạ thứ hai D : g c lệch tia ló so với tia ... nsinr2 (2) A = r1 + r2 (3) D = i1 + i2 – A (4) Hỏi nhanh: D a vào quan hệ g c tam gi c, chứng minh c ng th c (3) (4) Chú ý: Trong c ng th c ta gọi n chiết suất lăng kính, chiết suất tương đối chất...

Ngày tải lên: 18/05/2015, 16:09

... factor With the obtained analytic formulas, we carried out correcting detection efficiency with standard sample IAEA-375 The agreement between calculated activities with self-absorption correction ... were calculated by formula (2) Calculated results were presented in Table Table Detection efficiencies at some investigated energies of standard sample IAEA-375 Radionuclide 137 212 Pb 214 ( Cs ... high energy above 100 keV, the matrix correction between measured and standard samples can be neglected So, the standard sample preparation will be easier, saving time and cost to obtain the acceptable...

Ngày tải lên: 11/08/2016, 16:19

... Trường/Viện /C ng ty sở bán chương trình đào tạo cho người h c đ c lập sở kh c - E – learning C nhiều quan điểm, định ngh a kh c e - learning, trích số định ngh a e - learning đ c trưng nhất:  E - learning ... kh c th c m c c c hay tồn c c ( MASIE Center)  Vi c sử dụng c ng nghệ để tạo ra, đ a liệu c giá trị, thơng tin, h c tập kiến th c với m c đích nâng cao hoạt động tổ ch c phát triển khả c nhân ... h c biết mổ xẻ vấn đề thành yếu tố x c định mối liên hệ yếu tố - Website: website tập hợp trang web c đ a Internet dùng để định rõ vị trí Một trang web (web page) hồ sơ web Trang chủ website...

Ngày tải lên: 08/09/2016, 10:13

... INTRODUCTION Once we have expressed a double integral as an iterated integral, we can then evaluate it by calculating two single integrals INTRODUCTION Suppose that f is a function of two variables ... since ∫ b a g ( x) dx is a constant Equation ITERATED INTEGRALS Hence, in this case, the double integral of f can be written as the product of two single integrals: b d a c g ( x ) h ( y ) dA ... = b, we get: ∫ b a A( x) dx = ∫  ∫ f ( x, y ) dy  dx  a   c b d ITERATED INTEGRAL The integral on the right side of Equation is called an iterated integral Equation ITERATED INTEGRALS Thus,...

Ngày tải lên: 27/09/2016, 14:53

... continuous function f has the property that a small change in x produces only a small change in f(x) In fact, the change in f(x) can be kept as small as we please by keeping the change in x sufficiently ... However, discontinuities occur in such situations as electric currents  See Example in Section 1.3, where the Heaviside function is discontinuous at because lim H (t ) t →0 does not exist Geometrically, ... P16 CONTINUITY Figure shows the graphs of the functions in Example  In each case, the graph can’t be drawn without lifting the pen from the paper—because a hole or break or jump occurs in the...

Ngày tải lên: 27/09/2016, 14:53

... because each y-coordinate is increased by the same number c  Similarly, if g(x) = f(x - c) ,where c > 0, then the value of g at x is the same as the value of f at x - c (c units to the left of ... stretching and reflecting transformations  If c > 1, then the graph of y = cf(x) is the graph of y = f(x) stretched by a factor of c in the vertical direction  This is because each y-coordinate is ... multiplied by the same number c STRETCHING AND REFLECTING  The graph of y = -f(x) is the graph of y = f(x) reflected about the x-axis because the point (x, y) is replaced by the point (x, -y) TRANSFORMATIONS...

Ngày tải lên: 27/09/2016, 14:53

... this allows the micelle to be attracted to water and stay suspended 13 The polar heads of the micelles attract them to the water, and simultaneously repel other micelles so they will not coalesce ... (nonpolar) “tail” part of the molecule is attracted to water, but the majority of it isn’t the nonpolar tail tends to coagulate together to form a spherical structure called a micelle 11 12 Soap Action ... particles suspended in a medium the difference between colloids and regular suspensions is generally particle size – colloidal particles are from to 100 nm in size Properties of Colloids • the particles...

Ngày tải lên: 27/09/2016, 14:53

... and water, which will have the larger change in temperature? The iron They will have equal changes since the same amount of heat is added to each The Water None of the above Example Calculation ... Engines  If we can create an “engine” that operates in a cycle, we return to our starting point each time and therefore have the same internal energy Thus, for a complete cycle Q=W Model Heat Engine ... simulation Convection Examples  Ocean Currents  Plate tectonics Radiation Everything that has a temperature radiates energy  Method that energy from sun reaches the earth  Q 4 P = = σeAT = (const...

Ngày tải lên: 27/09/2016, 14:53

... alternate lighter and darker regions in the pattern are called Moiré fringes The perpendicular distance, D, between adjacent Moiré fringes depends on the angle, α, between the sets of lines on the ... image (b) (i) Make readings to determine the mean distance, xG, between the centre of the first-order green diffracted images and the centre of the slit You should this by looking at the scale ... distances from the centre of the slit The slit is vertically above a half-metre ruler, with the card at right angles to the ruler Figure vertical slit at the centre of the card LED half-metre ruler...

Ngày tải lên: 03/10/2016, 12:47

... percentage uncertainty in V2 = (2 marks) (d) The percentage uncertainty in the resistance of the 2.2 Ω resistor is 5% Calculate the percentage uncertainty in the resistance of the wire ... from clips C1 and C2 then repeat the procedure in part (a) (ii) to read values of θ when each of the remaining resistors of known resistance R are connected, in turn, between clips C1 and C2 Record ... Wire is manufactured in certain diameters under a system known as the English Standard Wire Gauge, each diameter of wire being identified by a particular SWG number Table shows the diameter of...

Ngày tải lên: 03/10/2016, 12:47

... out after candidates have acquired the necessary skills and after the appropriate sections of the specification have been taught so that candidates are familiar with any specialist apparatus ... malpractice Guidance on malpractice is contained in the JCQ document Suspected Malpractice in Examinations and Assessments: Policies and Procedures The Examinations Officer should give copies ... minutes except where candidates have been granted additional time by AQA Administration Candidates must not bring any paper-based materials into any session or take any assessment materials away at...

Ngày tải lên: 03/10/2016, 12:48

... malpractice Guidance on malpractice is contained in the JCQ document Suspected Malpractice in Examinations and Assessments: Policies and Procedures The Examinations Officer should give copies ... after candidates have acquired the necessary skills and after the appropriate sections of the specification have been taught so that candidates are familiar with any specialist apparatus involved ... Section B EMPA written test In extreme circumstances, when such arrangements are not possible, the teacher can supply a candidate with class data In this case, there will be no evidence for Task...

Ngày tải lên: 03/10/2016, 12:48

... 20 and 30 indicated in the table The table has been partly completed for you Use the additional columns in the table as required, to record repeated measurements An the amplitude of the pendulum ... in a vertical plane, directly above the ruler (a) (i) Record in the table below, An, the amplitude of the oscillation of the golf ball after n oscillations have been completed; use the values ... taped to solar cell Filter F1 has been taped to the surface of the solar cell that is sensitive to light The cell has been mounted on a box which has been fixed to the bench A cylindrical tube...

Ngày tải lên: 03/10/2016, 12:48

... carried out after candidates have acquired the necessary skills and after the appropriate sections of the specification have been taught so that candidates are familiar with any specialist apparatus ... malpractice Guidance on malpractice is contained in the JCQ document Suspected Malpractice in Examinations and Assessments: Policies and Procedures The Examinations Officer should give copies ... both circular shapes and remove the shaded circles at the centre of each Take one of these and place it, printed side down, on the bench Tape Polaroid square on to the card so that the square completely...

Ngày tải lên: 03/10/2016, 12:48

... estimate the magnitude of the electrostatic force between various charge configurations Permittivity of free space, 0 Appreciation that air can be treated as a vacuum when calculating force between ... three coplanar forces acting at a point using a force board velocity/speed, mass, force/weight, acceleration, displacement/distance Addition of vectors by calculation or scale drawing Calculations ... circular path at constant speed implies there is an acceleration and requires a centripetal force MS 0.4 Magnitude of angular speed  = v r = 2 f Radian measure of angle Estimate the acceleration...

Ngày tải lên: 03/10/2016, 13:27

... (trư c che) Sai Sai Sai C u Để hai sóng tần số truyền theo chiều giao thoa với với nhau, chúng phải c điều kiện sau đây? A C ng biên độ pha B C ng biên độ ngư c pha C Cùng biên độ hiệu số pha không ... theo thời gian Sai D Hiệu số pha không đổi theo thời gian §óng Sai Sai C u Chọn c u Đúng Hai sóng tần số phương truyền, gọi sóng kết hợp, c : A C ng biên độ pha Sai B C ng biên độ hiệu số pha ... sáng Phần giao hai chùm ánh sáng tạo vân sáng tối th a mãn điều kiện giao thoa: c tần số độ lệch pha không đổi theo thời gian Thay kính l c đỏ kính l c vàng, l c, tím… khoảng c ch vân sáng...

Ngày tải lên: 02/11/2012, 14:53