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Physical Science: Electromagnetism - Class -IX

Description: electromagnetism,solenoids,induction,transformers,Science,Physics,grade 9
Number of Questions: 15
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Tags: science
Attempted 0/15 Correct 0 Score 0

What uses induction to change mechanical energy to electrical energy (the opposite of a motor)?

  1. transformers

  2. electric generators

  3. semiconductors

  4. conductors


Correct Option: B

What uses induction to increase or decrease the voltage of alternating currents?

  1. generators

  2. semiconductors

  3. transformers

  4. insulators


Correct Option: C

Using a magnetic field to create an electric current within a wire is known as:

  1. reverse currents

  2. current opposition

  3. electromagnetic transformation

  4. electromagnetic induction


Correct Option: D

What scientist discovered magnetic fields can create electric currents not just vice versa?

  1. Hans Christian Oersted

  2. Michael Faraday

  3. Albert Einstein

  4. Joseph Henry


Correct Option: B

What energy transformation occurs within an electric motor?

  1. mechanical to electric

  2. chemical to electric

  3. electric to mechanical

  4. chemical to mechanical


Correct Option: C

What device is used to measure the strength and direction of an electric current in a wire?

  1. galvanometer

  2. commutator

  3. ionometer

  4. amperometer


Correct Option: A

T/F: Incredibly fast maglev trains use powerful electromagnets to levitate above the tracks.

  1. TRUE

  2. FALSE


Correct Option: A

Which of the following objects does NOT use an electromagnet for power?

  1. doorbell

  2. light bulb

  3. hair dryer

  4. MRI machine


Correct Option: B

Which has a stronger magnetic field?

  1. a solenoid

  2. an electromagnet


Correct Option: B

Once an iron core is placed into the coil of a solenoid, it becomes:

  1. an electromagnet

  2. a motor

  3. a transformer

  4. a semiconductor


Correct Option: A

Increasing the number of coils in a solenoid also increases the strength of ______.

  1. the protons

  2. the magnetic field

  3. the induction

  4. none of the above


Correct Option: B

What produces a magnetic field using a coil of wire to carry an electric current?

  1. compass

  2. generator

  3. transformer

  4. solenoid


Correct Option: D

T/F: Oersted discovered an electric current's direction affects the magnetic field around it.

  1. TRUE

  2. FALSE


Correct Option: A

Which scientist accidentally discovered the connection between electricity & magnets in 1820?

  1. Hans Christian Oersted

  2. Albert Einstein

  3. Michael Faraday

  4. Joseph Henry


Correct Option: A

Electromagnetism occurs when electric currents interact with ________.

  1. opposite ions

  2. magnetic fields

  3. metallic substances

  4. water


Correct Option: B
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