CHAPTER 6.2 : TYPE OF CURRENT & TRANSFORMERS

CHAPTER 6.2: TYPE OF CURRENT & TRANSFORMERS

How to increase or decrease voltage?

Multiple Select

Name the two types of current.

• Alternating current (AC)

• Direct current (DC)

• Reverse current (RC)

• Linear current (LC)

Multiple Choice

The current that flows in one direction is called ..............

• Alternating current (AC)

• Direct current (DC)

Multiple Choice

Which of the following is NOT the source of direct current (DC)?

Multiple Choice

Which type of current generated by this simple dynamo?

• Alternating current (AC)

• Direct current (DC)

Multiple Choice

The current that can flow reversely is known as ..............

• AC

• DC

Multiple Choice

Which of the following electrical appliance is NOT using alternating current (AC)?

• Hair dryer

• Smart phone

• Television

• Microwave

Multiple Choice

What is the type of current shown by this oscilloscope?

• AC

• DC

Multiple Select

What are DC has compared to AC?

• Does not have amplitude

• Does not have frequency

• Has amplitude

• Has frequency

Multiple Choice

Name the device that can be used to determine the frequency of alternating current?

• Osciloscope

• Telescope

• Microscope

• Stetoscope

Multiple Choice

Name the device that can be used to change the voltage of alternating current?

• Transformers

• Transistor

• Resistor

• Inverter

Multiple Select

Select ALL the materials needed for building a transformer?

• Soft iron core

• Primary coil

• Secondary coil

• Input voltage

• Magnet

Multiple Choice

Why do we need to use a transformers?

• Adjust the voltage

• Save the voltage

• Convert AC to DC

• Maintain the current

Multiple Choice

Name this type of transformers?

• Step-up transformer

• Step-down transformer

Multiple Select

Select ALL the characteristics of this type of transformers.

• Step-down transformer

• Primary coil is less than secondary coil

• Produce less voltage

• Use AC only

• Does not need iron core

Multiple Choice

Which of the following is the correct ratio involved in the transformers?

• $\frac{Vp}{Vs}=\frac{Np}{Ns}$

• $\frac{Vp}{Vs}=\frac{Ns}{Np}$

Multiple Choice

 $\frac{Vp}{Vs}=\frac{Np}{Ns}$  Which of the following is INCORRECT about the formula involved transformers?

• Vp = Primary/Input voltage

• Ns = Number of secondary coil

• Np = Number of iron core

• Vs = Secondary/output voltage

Multiple Choice

If the input voltage is 6V, the number of the primary coils and secondary coil are 12 and 6 respectively. Calculate output voltage.

• 3V

• 6V

• 12V

• 24V