Theory

CH24 - ALTERNATING CURRENTS

A sinusoidal alternating voltage is to be rectified. (a) Suggest one advantage of full-wave rectification as compared with half-wave rectification.&n...

2009 Winter

Theory

CH24 - ALTERNATING CURRENTS

A student is asked to design a circuit by which a direct voltage of peak value 9.0V is obtained from a 240V alternating supply. The student uses a tra...

2010 Summer

Theory

CH24 - ALTERNATING CURRENTS

(a) Explain what is meant by the $\textit{root-mean-square}$ (r.m.s.) value of an alternating voltage.  [2] (b) An alternating voltage $V$ is re...

2010 Summer

Theory

CH24 - ALTERNATING CURRENTS

The variation with time $t$ of the current $I$ in a resistor is shown in Fig. 6.1. The variation of the current with time is sinusoidal. (a) Expla...

2010 Winter

Theory

CH24 - ALTERNATING CURRENTS

An alternating current supply is connected in series with a resistor R, as shown in Fig. 6.1. The variation with time $t$ (measured in seconds) of ...

2011 Summer

Theory

CH24 - ALTERNATING CURRENTS

An alternating current supply is connected in series with a resistor R, as shown in Fig. 6.1. The variation with time $t$ (measured in seconds) of ...

2011 Summer

Theory

CH24 - ALTERNATING CURRENTS

The variation with time $t$ of the output $V$ of an alternating voltage supply of frequency 50 Hz is shown in Fig. 6.1.(a) Use Fig. 6.1 to state (i) t...

2011 Winter

Theory

CH24 - ALTERNATING CURRENTS

The variation with time $t$ of the output $V$ of an alternating voltage supply of frequency 50 Hz is shown in Fig. 6.1. (a) Use Fig. 6.1 to state ...

2011 Winter

Theory

CH24 - ALTERNATING CURRENTS

The components for a bridge rectifier are shown in Fig. 5.1. (a) Complete the circuit of Fig. 5.1 by showing the connections of the supply and of t...

2011 Winter

Theory

CH24 - ALTERNATING CURRENTS

A sinusoidal alternating voltage supply is connected to a bridge rectifier consisting of four ideal diodes. The output of the rectifier is connected t...

2012 Summer

MCQ

CH1 - PHYSICAL QUANTITIES & UNITS

Which quantity with its unit is correct?

2016 Summer

MCQ

CH1 - PHYSICAL QUANTITIES & UNITS

The luminosity $L$ of a star is given by $L = 4\pi r^2 \sigma T^4$ where $r$ is the radius of the star, $T$ is the temperature of the star, $\sig...

2016 Summer

MCQ

CH1 - PHYSICAL QUANTITIES & UNITS

The diagram shows two vectors X and Y, drawn to scale. If X = Y − Z, which diagram best represents the vector Z?

2016 Summer

MCQ

CH2 - MEASUREMENT TECHNIQUES

The diagram shows a cathode-ray oscilloscope (c.r.o.) being used to measure the rate of rotation of a flywheel.The flywheel has a small magnet M mount...

2016 Summer

MCQ

CH2 - MEASUREMENT TECHNIQUES

A student determines the density $\rho$ of steel by taking measurements from a steel wire. mass $m = 6.2 \pm 0.1 \text{ g}$ length $l = 25.0 \pm 0.1 \...

2016 Summer

MCQ

CH3 - KINEMATICS

The acceleration of free fall on the Moon is $1.6 \, \text{m}\,\text{s}^{-2}$. The Moon has no atmosphere. An astronaut standing on the surface of the...

2016 Summer

MCQ

CH3 - KINEMATICS

A tennis ball is released from rest at the top of a tall building. Which graph best represents the variation with time $t$ of the acceleration $a$ of ...

2016 Summer

MCQ

CH3 - KINEMATICS

The graph shows how the velocity $v$ of an object moving in a straight line varies with time $t$ from $t = 0$ to $t = T$. Which graph represents th...

2016 Summer

MCQ

CH4 - DYNAMICS

A ball falls vertically onto horizontal ground and rebounds, as shown. The ball has momentum $p_1$ downwards just before hitting the ground. After ...

2016 Summer

MCQ

CH4 - DYNAMICS

A sphere falls from rest through the air. The graph shows the variation with time of the sphere’s velocity. Which diagram shows the forces ac...

2016 Summer