The correct answer is: C. Anywhere between 75% and 90%.
The efficiency of a motor is the ratio of the output power to the input power. The output power is the mechanical power that the motor produces, while the input power is the electrical power that the motor consumes. The efficiency of a motor can be affected by a number of factors, including the design of the motor, the quality of the materials used, and the operating conditions.
In general, the efficiency of a DC motor is between 75% and 90%. However, the efficiency can vary depending on the specific motor and the operating conditions. For example, a motor that is operated at a high speed will have a lower efficiency than a motor that is operated at a low speed.
The efficiency of a motor is an important factor to consider when choosing a motor for a particular application. A motor with a higher efficiency will consume less power and generate less heat, which can lead to lower operating costs and a longer lifespan.
Here is a brief explanation of each option:
- Option A: 100% efficiency is not possible for a DC motor. There will always be some losses in the motor, such as friction and heat losses.
- Option B: Around 90% efficiency is a good estimate for the efficiency of a DC motor. However, the efficiency can vary depending on the specific motor and the operating conditions.
- Option C: Anywhere between 75% and 90% is the correct answer. This is the range of efficiency that is typically achieved by DC motors.
- Option D: Less than 50% efficiency is possible for a DC motor, but it is not typical. A motor with an efficiency of less than 50% is likely to be inefficient and may not be a good choice for a particular application.