[Maximum number: 1]

Data analysis question.

A student sets up a circuit to study the variation of resistance R of a negative temperature coefficient (NTC) thermistor with temperature T. The data are shown plotted on the graph.

(a)

The electric current through the thermistor for $T=283 \mathrm{~K}$ is 0.78 mA . The uncertainty in the electric current is 0.01 mA .

[ 1 ]

(i)

Calculate the power dissipated by the thermistor at $T=283 \mathrm{~K}$ .

[ 1 ]

[Maximum number: 5]

A girl rides a bicycle that is powered by an electric motor. A battery transfers energy to the electric motor. The emf of the battery is 16 V and it can deliver a charge of 43 kC when discharging completely from a full charge.

(a)

The bicycle has a meter that displays the current and the terminal potential difference (pd) for the battery when the motor is running. The diagram shows the meter readings at one instant. The emf of the cell is 16 V .

Determine the internal resistance of the battery.

[ 2 ]

(b)

The battery is made from an arrangement of 10 identical cells as shown.

Calculate

[ 3 ]

(i)

the emf of one cell.

[ 1 ]

(ii)

the internal resistance of one cell.

[ 2 ]

[Maximum number: 2]

A student investigates the electromotive force (emf) $\varepsilon$ and internal resistance r of a cell.

The current I and the terminal potential difference V are measured.
For this circuit $V=\varepsilon-I r$ .
The table shows the data collected by the student. The uncertainties for each measurement are shown.

The graph shows the data plotted.

(a)

Outline, without calculation, how the internal resistance can be determined from this graph.

[ 2 ]

[Maximum number: 7]

The resistance R of a wire of length L can be measured using the circuit shown.

(a)

In one experiment the wire has a uniform diameter of $d=0.500 \mathrm{~mm}$ . The graph shows data obtained for the variation of R with L.

The gradient of the line of best fit is $6.30 \Omega \mathrm{~m}^{-1}$ .

[ 5 ]

(i)

Estimate the resistivity of the material of the wire. Give your answer to an appropriate number of significant figures.

[ 2 ]

(ii)

Explain, by reference to the power dissipated in the wire, the advantage of the fixed resistor connected in series with the wire for the measurement of R.

[ 3 ]

(b)

The experiment is repeated using a wire made of the same material but of a larger diameter than the wire in part (a). On the axes in part (a), draw the graph for this second experiment. provided.

[ 2 ]

[Maximum number: 1]

In an experiment to measure the specific latent heat of vaporization of water $L_{\mathrm{v}}$ , a student uses an electric heater to boil water. A mass m of water vaporizes during time $t . \quad L_{\mathrm{v}}$ may be calculated using the relation

L_{\mathrm{v}}=\frac{V I t}{m}

where V is the voltage applied to the heater and I the current through it.

(a)

Outline why, during the experiment, V and I should be kept constant.

[ 1 ]

[Maximum number: 1]

The circuit shown may be used to measure the internal resistance of a cell.

(a)

An ammeter and a voltmeter are connected in the circuit. Label the ammeter with the letter A and the voltmeter with the letter V.

[ 1 ]

[Maximum number: 6]

An experiment to find the internal resistance of a cell of known emf is to be set.
The following equipment is available:

(a)

Draw a suitable circuit diagram that would enable the internal resistance to be determined.

[ 1 ]

(b)

It is noticed that the resistor gets warmer. Explain how this would affect the calculated value of the internal resistance.

[ 3 ]

(c)

Outline how using a variable resistance could improve the accuracy of the value found for the internal resistance. provided.

[ 2 ]

[Maximum number: 3]

An electrical circuit is used during an experiment to measure the current I in a variable resistor of resistance R. The emf of the cell is a and the cell has an internal resistance r.

A graph shows the variation of $\frac{1}{I}$ with R.

(a)

Show that the gradient of the graph is equal to $\frac{1}{\mathrm{e}}$ .

[ 2 ]

(b)

State the value of the intercept on the R axis.

[ 1 ]

[Maximum number: 4]

The graph shows the variation with the potential difference V of the current I in an ohmic resistor P and a non-ohmic component Q .

(a)

Calculate the resistance of P.

[ 1 ]

(b)

Outline how the resistance of Q changes when the current in it increases.
P and Q are connected in a circuit with a cell of negligible internal resistance as shown. The ammeter and the voltmeter are ideal.

The reading of the voltmeter is 3.0 V .

[ 1 ]

(c)

Determine the emf of the cell.

[ 2 ]

[Maximum number: 1]

A wire of length L is used in an electric heater. When the potential difference across the wire is 200 V , the power transferred in the wire is 500 W . A second wire is made from the same metal and has the same cross-sectional area. When a potential difference of 400 V is applied across the second wire, the power transferred is 2000 W .

What is the length of the second wire?

A

$\frac{L}{4}$

B

$\frac{L}{2}$

C

L

D

2 L

Question 1

Question 1(d)

Question 1(d)(i)

Question 1

Question 1(d)

Question 1(e)

Question 1(e)(i)

Question 1(e)(ii)

Question 1

Question 1(c)

Question 2

Question 2(a)

Question 2(a)(i)

Question 2(a)(ii)

Question 2(b)

Question 2

Question 2(a)

Question 2

Question 2(a)

Question 2

Question 2(a)

Question 2(b)

Question 2(c)

Question 2

Question 2(a)

Question 2(b)

Question 3

Question 3(a)

Question 3(b)

Question 3(d)

Question 9