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Question 1

SLPaper 2

Electrical resistors can be made by forming a thin film of carbon on a layer of an insulating material.

A.carbon film resistor is made from a film of width 8.0 mm and of thickness 2.0 μm. The diagram shows the direction of charge flow through the resistor.

Diagram

1.

The resistance of the carbon film is 82 Ω. The resistivity of carbon is 4.1x 10^{-5} Ω m. Calculate the length l of the film.

[1]

2.

The film must dissipate a power less than $1500$ W from each square metre of its surface to avoid damage. Calculate the maximum allowable current for the resistor.

[2]

3.

State why knowledge of quantities such as resistivity is useful to scientists.

[1]

4.

The current direction is now changed so that charge flows vertically through the film.

Deduce, without calculation, the change in the resistance.

[2]

5.

Draw a circuit diagram to show how you could measure the resistance of the carbon-film resistor using a potential divider arrangement to limit the potential difference across the resistor.

[2]

Question 2

SLPaper 1

P and Q are two opposite point charges. The force F acting on P due to Q and the electric field strength E at P are shown.

Which diagram shows the force on Q due to P and the electric field strength at Q?

Question 3

SLPaper 1

In the circuit shown, the fixed resistor has a value of 3 Ω and the variable resistor can be varied between 0 Ω and 9 Ω.

circuit

The power supply has an emf of 12 V and negligible internal resistance. What is the difference between the maximum and minimum values of voltage (V) across the 3 Ω resistor?

Question 4

SLPaper 1

A circuit consists of a cell of emf $E = 3.0$ V and four resistors connected as shown. Resistors $R_1$ and $R_4$ are 1.0 Ω and resistors $R_2$ and $R_3$ are 2.0 Ω.

What is the voltmeter reading?

Circuit Diagram

Question 5

SLPaper 1

The diagram shows two current-carrying wires, P and Q, that both lie in the plane of the paper. The arrows show the conventional current direction in the wires.

Physics-17N.1.SL.TZ0.20-q-1.png

The electromagnetic force on Q is in the same plane as that of the wires. What is the direction of the electromagnetic force acting on Q?

Physics-17N.1.SL.TZ0.20-q-2.png

Question 6

SLPaper 1

A particle of mass m and charge of magnitude q enters a region of uniform magnetic field B that is directed into the page. The particle follows a circular path of radius R. What are the sign of the charge of the particle and the speed of the particle?

Physics-18N.1.SL.TZ0.22-q-1.png

Question 7

SLPaper 1

A combination of four identical resistors each of resistance R are connected to a source of emf ε of negligible internal resistance. What is the current in the resistor X?

Question 8

SLPaper 1

A liquid that contains negative charge carriers is flowing through a square pipe with sides A, B, C and D. A magnetic field acts in the direction shown across the pipe.

On which side of the pipe does negative charge accumulate?

Question 9

SLPaper 1

An electric motor of efficiency 0.75 is connected to a power supply with an emf of 20 V and negligible internal resistance. The power output of the motor is $120 W$ . What is the average current drawn from the power supply?

Question 10

HLPaper 1

An electron enters the space inside a current-carrying solenoid. The velocity of the electron is parallel to the solenoid's axis. The electron is

Topic 5 - Electricity and Magnetism

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