Answer and Explanation:
Commutator are used in DC machine commutator is mainly used for the reversing the direction of the current .It is connected to the armature of the DC generator or motor
ADVANTAGE OF COMMUTATOR The main advantage of the commutator in DC motor is to keep keep the direction of the toque always in the same direction by changing the current direction
DISADVANTAGE OF COMMUTATOR : The main disadvantage is due to the friction between the commutator and brushes there is a friction loss.
Answer:
Three objectives of a tariff are
1) To control trade between countries
2) To protect domestic industries
3) To provide a source of income
Three characteristics of a tariff are;
1) Adequate return
2) Attractive
3) Fairness
Explanation:
A tariff is an import or export tax placed on goods traded between countries, it serves to control the foreign trade between the two countries and to protect or develop local industry
A Tariff is an important source of income to countries
Three characteristics of a tariff are;
1) Adequate return
Proper return from the consumer should be factored in a tariff to account for the alternatives or normal expense pattern
2) Attractive
The tariff should be attractive to encourage consumption of electricity or complimentary goods
3) Fairness
Based on the consumption of related resources brought about by large scale utilization, large consumer tariff should be lower than those that consume less complementary resources.
Answer:
The answer is below
Explanation:
1) The synchronous speed of an induction motor is the speed of the magnetic field of the stator. It is given by:

2) The speed of the rotor is the motor speed. The slip is given by:

3) The frequency of the rotor is given as:

4) At standstill, the speed of the motor is 0, therefore the slip is 1.
The frequency of the rotor is given as:
