* not completed

. The Rance Estuary barrage in France has a capacity of 240 MW. In which year did it first produce electrical output from its turbines?

1966 correct incorrect

1981 correct incorrect

1996 correct incorrect

* not completed

. Tidal barrage and tidal stream systems both harness the energy of the tides. Which form of energy do tidal stream systems tap into?

Electrical energy correct incorrect

Potential energy correct incorrect

Kinetic energy correct incorrect

* not completed

. When are the spring tides produced?

Only in the spring correct incorrect

When the Sun and Moon are at 90� to each other correct incorrect

When the Sun and Moon are in line with the Earth correct incorrect

* not completed

. The power output of a tidal barrage is roughly proportional to:

the tidal range correct incorrect

the square of the tidal range correct incorrect

the cube of the tidal range correct incorrect

* not completed

. The tides around the UK have a 12.4 hour cycle. A barrage such as that proposed for the River Severn would operate mainly with ebb generation. It would produce:

one pulse of power every 12.4 hours around low tide correct incorrect

one pulse of power every 12.4 hours around high tide correct incorrect

two pulses of power every 12.4 hours correct incorrect

* not completed

. If built, a Cardiff-Weston Severn Barrage would raise the average water level in the Severn Estuary where many birds feed on the mud flats. By how much might this Barrage reduce the area of exposed intertidal habitat on mud flats?

10 square kilometres correct incorrect

50 square kilometres correct incorrect

over 150 square kilometres correct incorrect

* not completed

. If every practical UK tidal barrage scheme was developed how much electricity would they produce?

27 TWh correct incorrect

53 TWh correct incorrect

106 TWh correct incorrect

* not completed

. A major part of the UK tidal stream resource is in the Pentland Firth. Whereabouts in the UK is this?

Between South Wales and Devon correct incorrect

Between Northern Ireland and Scotland correct incorrect

Between the Orkney Islands and the northern Scottish mainland correct incorrect

* not completed

. The available energy in the water for a tidal stream turbine depends on the rotor blade length and the water velocity. It is proportional to:

The blade length and the square of the velocity correct incorrect

The square of the blade length and the square of the velocity correct incorrect

The square of the blade length and the cube of the velocity correct incorrect

* not completed

. The MCT Seagen tidal stream device has two rotors. How do they adjust to the change in direction of the tide?

The whole device turns round on its tower correct incorrect

The pitch of the blades can be rotated through 180° correct incorrect

Only one turbine is used in each direction correct incorrect