Tag: oersted's experiment

Questions Related to oersted's experiment

What will happen if the strip in a doorbell loses its flexibility?

  1. Striker may break if current is large.

  2. After hitting the metal gong, it never returns to original position and only a single sound is produced.

  3. System of doorbell breaks

  4. Both A and B


Correct Option: D
Explanation:

Because of lack of flexibility, striker will resist change of motion more and may break if current is large.

Without flexibility, no rebounding force is present and striker will not return to its original position.

What is the use of flexibility strip in a doorbell?

  1. It brings back striker to its original position

  2. It supports the motion of the striker

  3. It completes the electric circuit flexibly

  4. Its a safety precaution


Correct Option: A
Explanation:

Without the flexibility strip, the striker will not come back to original position when the electrical circuit breaks.

Electric doorbell

  1. Always consume power

  2. Consume power only when switch is pressed

  3. Do not consume power practically and needs only starting power

  4. cant say


Correct Option: B
Explanation:

When switch is pressed, circuit completes and ringing begins. Hence, electrical energy is converted to sound energy. As switch is released, no current flows and no energy is consumed,

Exposed Electric doorbell can be damaged by 

  1. Mechanical damage

  2. High Electric currents

  3. Humidity

  4. All of the above


Correct Option: D
Explanation:

Mechanical Damage to metal gong or striker may hinder working of the bell.

High electric currents may cause heating and burning of electrical circuit.
Humidity may cause short circuit between two unconnected wires, causing high electric currents and damage.

During a doorbell ringing

  1. Current always flows in the circuit

  2. Electromagnet is always present

  3. Striker is always in contact with metal gong

  4. Striker always repeatedly hits metal gong


Correct Option: D
Explanation:

Striker repeatedly hits the metal gong when doorbell is ringing. 

This can be observed in regular bells used at homes.

Armature is pulled towards the spring when it strikes the gong because

  1. The electromagnet gets demagnetized

  2. The current flow breaks

  3. Spring effect

  4. All of the above


Correct Option: D
Explanation:

The working of an electric magnet is based on the magnetic effect of current. When the key is pressed the circuit gets completed and current passes through it causing the electromagnet to get magnetized which in turn attracts the armature. This movement of the armature causes the hammer to strike the gong. However when the armature moves towards the gong the connection between the spring strip and adjusting screw is lost which breaks the circuit and the current flow is stopped thus demagnetizing the electromagnet. This causes the armature to return to its original position and it is thus pulled back due to the spring effect of the spring strip. This process is called a make and break circuit.

Which process is applied on a circuit for the working of an electric bell?

  1. Magnetization

  2. Make and break

  3. Both A and B

  4. None of the above


Correct Option: B
Explanation:

The working of an electric magnet is based on the magnetic effect of current. When the key is pressed the circuit gets completed and current passes through it causing the electromagnet to get magnetized which in turn attracts the armature. This movement of the armature causes the hammer to strike the gong. However when the armature moves towards the gong the connection between the spring strip and adjusting screw is lost which breaks the circuit and the current flow is stopped thus demagnetizing the electromagnet. This causes the armature to return to its original position and it is thus pulled back due to the spring effect of the spring strip. This process is called a make and break circuit.

The hammer hits the gong because

  1. It has electric charge

  2. It displays the spring effect

  3. It is attracted towards the electro-magnet

  4. All of the above


Correct Option: C
Explanation:

The working of an electric magnet is based on the magnetic effect of current. When the key is pressed the circuit gets completed and current passes through it causing the electromagnet to get magnetized which in turn attracts the armature. This movement of the armature causes the hammer to strike the gong.

The strength and direction of the magnetic field depends on ..........

  1. Magnitude of electric current

  2. Direction of electric current

  3. Both A and B

  4. None of the above


Correct Option: C
Explanation:

In his experiment Oersted observed that the deflection of the needle compass changed according to the direction of the current and also as the current in the wire increased, the deflection of the needle increased. Thus he inferred that the strength and direction of the magnetic field depends on the magnitude and direction of current.

Which of the following effects of current does not depend on the direction of current?

  1. Lighting and chemical effects

  2. Heating and lighting effects

  3. Heating and magnetic effects

  4. Magnetic and chemical effects


Correct Option: B
Explanation:

Heating effect and lighting effect does not depend on the direction of current.