Поставьте следующие предложения в вопросительной и отрицательной формах: 1. Electric motors and generators are used to convert mechanical energy into electrical energy.
2. A machine that converts mechanical energy into electrical energy is called a generator.
3. A machine that converts electrical energy into mechanical energy is called a motor.
4. The British scientist Michael Faraday discovered the principle of electromagnetic induction in 1831.
5. The French physicist Andre Marie Ampere first observed electromagnetic reaction in 1820.
6. The magnetic field of a permanent magnet is strong enough to operate only a small motor.
7. Electromagnets are used for large machines.
8. Motors and generators consist of two basic units.
9. The armature is usually a laminated soft-iron core.