## Tuesday 21 August 2012

### PHYSICS LECTURE Part ONE & TWO - IBDP Video for Gr-12 – AHL on Topic-12- EMI

PHYSICS LECTURE Part ONE - IBDP Video for Gr-12 – AHL on Topic-12- EMI

PHYSICS LECTURE Part TWO -IBDP Video for Gr-12 – AHL on Topic-12- EMI

## Saturday 18 August 2012

### 1st, 2nd & 3rd PART of PHYSICS LECTURE - IBDP Video -Topic- IA PART 1 - Design ( D ) Lab on PRESSURE

FIRST PART of PHYSICS LECTURE - IBDP Video
-Topic- IA  PART 1 - Design ( D ) Lab on PRESSURE

SECOND  PART of PHYSICS LECTURE - IBDP Video
-Topic- IA  PART 1 - Design ( D ) Lab on PRESSURE

THIRD  PART of PHYSICS LECTURE - IBDP Video
-Topic- IA  PART 1 - Design ( D ) Lab on PRESSURE

## Thursday 16 August 2012

### IBDP-PHYSICS - Class Test No-2-Topic-5 &12-16th Aug, 2012

IBDP-PHYSICS - Class Test No-2-Topic-5 &12-16th Aug, 2012

1.       A positively charged rod is placed near to the cap of an uncharged gold leaf electroscope. Which one of the following diagrams correctly shows the distribution of charges on the electroscope as well as the deflection of the gold leaf?

(1)

2.       The graph below shows the current/voltage characteristics of a filament lamp.

The resistance of the filament at 4.0 V is
A.      250 Ω.
B.      4 000 Ω.
C.      8 000 Ω.
D.      64 000 Ω.
(1)

3.       An electric motor is used to raise a weight of 2.0 N. When connected to a 4.0 V supply, the current in the motor is 1.5 A. Assuming no energy losses, the best estimate for the maximum steady speed at which the weight can be raised is
A.      0.3 ms–1.
B.      3.0ms–1.
C.      9.0ms–1.
D.      12.0ms–1.
(1)

4.       Which one of the following correctly gives the number of electrons, protons and neutrons in a neutral atom of the nuclide Cu?
 Number of electrons Number of protons Number of neutrons A. 65 29 36 B. 29 36 29 C. 29 65 65 D. 29 29 36
(1)

5.       In the Geiger-Marsden experiment, α particles are moving upward to produce some MOTION. The experimental results indicate that we must apply,
A.      Fleming’s Left Hand Rule.
B.      Fleming’s Right Hand Rule.
C.      Right Hand Thumb Rule.
D.      Right Hand Thumb Rule.
(1)

6.       Unit of Magnetic Flux Density is,
A.      Volt / meter
B.      Ampere / Second.
C.      Tesla
D.      Weber / Meter
(1)

7.       The unified mass unit is defined as
A.      the mass of one neutral atom of C.
B.       of the mass of one neutral atom of C.
C.       of the mass of one neutral atom of C.
D.      the mass of the nucleus of C.
(1)

8.       A positively charged sphere falls vertically in a vacuum between two long parallel plates carrying opposite charges. Which one of the following diagrams best shows the path followed by the sphere?
(1)

9.       The diagram shows the electric field lines produced by an electrostatic focusing device.
Which one of the following diagrams best shows the corresponding equi-potential lines? The electric field lines are shown as broken lines on each of the diagrams.
(1)

10.     The diagram below shows the path XY of an electron that passes through a thin foil placed in a vacuum.

There is a uniform magnetic field acting perpendicularly to the plane of the page. Which one of the following statements best explains the path followed by the electron?
 Direction of motion of the electron Direction of the magnetic field A. Y to X into the plane of the page B. Y to X out of the plane of the page C. X to Y into the plane of the page D. X to Y out of the plane of the page
(1)

11.     When a coil is rotated in a uniform magnetic field at a certain frequency, the variation with time t of the induced e.m.f. E is as shown below.

The frequency of rotation of the coil is reduced to one half of its initial value. Which one of the following graphs correctly shows the new variation with time t of the induced e.m.f. E?
(1)

12.     The magnetic flux Φ through a coil having 500 turns varies with time t as shown below.
The magnitude of the e.m.f. induced in the coil is
A.      0.25 V.
B.      0.50 V.
C.      250 V.
D.      1 000 V.
(1)

13.     Which one of the following lists a fundamental unit and a derived unit?
 A. Ampere second B. coulomb kilogram C. coulomb newton D. metre kilogram
(1)

14.     A student measures the current in a resistor as 677 mA for a potential difference of 3.6 V. A calculator shows the resistance of the resistor to be 5.3175775 Ω. Which one of the following gives the resistance to an appropriate number of significant figures?
A.      5.3 Ω
B.      5.32 Ω
C.      5.318 Ω
D.      5.31765775 Ω
(1)

15.     A plastic rod is rubbed with a cloth. At the end of the process, the rod is found to be positively charged and the cloth is found to be uncharged. This involves the movement of
A.      positive charge from the cloth to the rod.
B.      positive charge from earth to the cloth.
C.      negative charge from the rod to earth.
D.      negative charge from earth to the cloth.
(1)

16.     Two charges of –e and +4e are fixed at the positions shown below. At which position along the line XY is the electric field due to these charges equal to zero?
(1)

17.     Which one of the following is a correct definition of electric potential difference between two points?
A.      The power to move a small positive charge between the two points.
B.      The work done to move a small positive charge between the two points.
C.      The power per unit charge to move a small positive charge between the two points.
D.      The work done per unit charge to move a small positive charge between the two points.
(1)

18.     The variation with potential difference V of the current I in an electric lamp is shown below.
At point P, the current is Ip, the potential difference is Vp and the gradient of the tangent to the curve is G. What is the resistance of the lamp at point P?
A.
B.      G
C.
D.
(1)

19.     A cell of e.m.f. E and internal resistance r is connected to a variable resistor. A voltmeter is connected so as to measure the potential difference across the terminals of the cell. Which one of the following is the correct circuit diagram of the arrangement?
(1)

20.     A strip of aluminium foil is held between the poles of a strong magnet, as shown below.

When a current is passed through the aluminium foil in the direction shown, the foil is deflected. In which direction is this deflection?
A.      Vertically downwards
B.      Vertically upwards
C.      Towards the North pole of the magnet
D.      Towards the South pole of the magnet
(1)

21.     The diagram shows a coil of wire that can rotate between the poles of a magnet about the axis XY.
A current is passed through the coil by means of a commutator connected to the ends of the coil. What is the position of the coil in the magnetic field so that its turning effect is a maximum and what is the position of the coil when the current is reversed so that the coil rotates continuously?
 plane of coil for maximum turning effect plane of coil for reversal of current A. parallel to direction of field parallel to direction of field B. normal to direction of field parallel to direction of field C. parallel to direction of field normal to direction of field D. normal to direction of field normal to direction of field
(1)

22.     The diagram below shows lines of electric equipotential. The change in potential on moving from one line to the next is always the same. At which point does the electric field strength have its greatest magnitude?
(1)

23. State the following five Laws in Electriciy and Magnetism with relevant formulae.             [8]
i.            Ohm’s Law
ii.            Law of resistors in SERIES Circuit
iii.            Law of resistors in  PARALLEL Circuit
iv.            Faraday’s Law of Electromagnetic induction.
v.            Lenz’s Law of Electromagnetic induction
vi.            Kirchhoff’s Current Law in a Circuit.
vii.            Kirchhoff’s Current Law in a Circuit.
viii.            Kirchhoff’s  VOLTAGE Law in a Circuit.

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