QUES: The BBC also introduced Ceefax, the first teletext service, starting in 1974. This service allows BBC viewers to view textual information such as the latest news on their television. CEEFAX has not made a full transition to digital television, instead being replaced by the new interactive BBCi service.

When was Ceefax launched?
What is the answer?
ANS: 1974
QUES: In the far north, there is a division between Berber-descendent Tuareg nomad populations and the darker-skinned Bella or Tamasheq people, due the historical spread of slavery in the region. An estimated 800,000 people in Mali are descended from slaves. Slavery in Mali has persisted for centuries. The Arabic population kept slaves well into the 20th century, until slavery was suppressed by French authorities around the mid-20th century. There still persist certain hereditary servitude relationships, and according to some estimates, even today approximately 200,000 Malians are still enslaved.

Wiser division in southern Mali?
What is the answer?
ANS: unanswerable
QUES: An advantage of the universal motor is that AC supplies may be used on motors which have some characteristics more common in DC motors, specifically high starting torque and very compact design if high running speeds are used. The negative aspect is the maintenance and short life problems caused by the commutator. Such motors are used in devices such as food mixers and power tools which are used only intermittently, and often have high starting-torque demands. Multiple taps on the field coil provide (imprecise) stepped speed control. Household blenders that advertise many speeds frequently combine a field coil with several taps and a diode that can be inserted in series with the motor (causing the motor to run on half-wave rectified AC). Universal motors also lend themselves to electronic speed control and, as such, are an ideal choice for devices like domestic washing machines. The motor can be used to agitate the drum (both forwards and in reverse) by switching the field winding with respect to the armature.

How is stepped speed control achieved?
What is the answer?
ANS:
Multiple taps on the field coil provide