Tag: oersted's experiment

Questions Related to oersted's experiment

Thermistor has a resistance of ________

physics electromagnetic forces oersted experiment oersted's experiment magnetic field due to a straight current carrying conductor

  1. 250 to 500 k ohms

  2. 50 to 10 k ohms

  3. 1 to 1 k ohms

  4. 100 to 100 k ohms

Show answer
Correct Option: D
Explanation:

Thermistor has a resistance range of 100 to 100 k. Thermistor consists of a mixture of metallic oxides of manganese, nickel, cobalt, copper, iron and uranium.

Thermistor material is pressed ________

physics electromagnetic forces oersted experiment oersted's experiment magnetic field due to a straight current carrying conductor

  1. under zero pressure

  2. under low pressure

  3. under high pressure

  4. under low volume

Show answer
Correct Option: C
Explanation:

A thermistor material is usually pressed under high pressure to form a flat cylindrical shape. Disks and washers are placed in series or in parallel to increase the power dissipation.

Thermistors have ________

physics electromagnetic forces oersted experiment oersted's experiment magnetic field due to a straight current carrying conductor

  1. positive temperature coefficient

  2. negative temperature coefficient

  3. zero temperature coefficien

  4. infinite temperature coefficient

Show answer
Correct Option: B
Explanation:

Thermistor generally has a negative temperature coefficient of resistance. With increase in temperature, resistance of a thermistor decreases.

Thermistor follows which law for small variations ________

physics electromagnetic forces oersted experiment oersted's experiment magnetic field due to a straight current carrying conductor

  1. Charles law

  2. KVL

  3. KCL

  4. Ohms law

Show answer
Correct Option: D
Explanation:

For small changes in the values of current, voltage across a thermistor increases. It attains a peak value. Then the voltage across the thermistor decreases. As a result Ohms law is followed at small variations of current.

Which of the following is/are correct?

physics magnetic effect of electric current oersted experiment oersted's experiment magnetic field due to a straight current carrying conductor

  1. Electric current can produce a magnetism

  2. Due to change in current the magnetic strength changes

  3. Magnetic strength of a magnet is independent of the number of turn in the current carrying coil

  4. All of the above

Show answer
Correct Option: D
Explanation:

I)According to Oersted experiment electric current can produce magnetism.

iI)Magnetic induction $B \alpha I$
If current changes the strength $B$ changes.
iiI)For circular coil magnetic field $B$ due to single ring $B=\dfrac{\mu _0 i}{2r}$
If magnet contain n turn then its strength is $B _2=nB$
But if current carrying coil have $n _2$ turn then strength doesn't change.
$B _2=nB$
Hence all options are correct.

A compass needle placed at a distance $r$ from a short magnet in $\tan\ A$ position shown a deflection of $60^{o}$. If the distance is increased to $r(3)^{1/3}$, then the deflected of the compass needle is:

physics magnetic effect of electric current oersted experiment oersted's experiment magnetic field due to a straight current carrying conductor

  1. $30^{o}$

  2. $60^{o}\ \times (3)^{1/3}$

  3. $60^{o}\ \times (3)^{2/3}$

  4. $90^{o}\ \times (3)^{1/3}$

Show answer
Correct Option: A

Electromagnet can be formed due to which of the following?

physics magnetic effect of electric current oersted experiment oersted's experiment magnetic field due to a straight current carrying conductor

  1. Heating effect of current

  2. Magnetic effect of current

  3. Chemical effect of current

  4. None of the above

Show answer
Correct Option: B
Explanation:

Electromagnets are formed by passing an electric current through a wire coiled around the substance with iron core. The electric current generates a magnetic field around the  substance and thus magnetize it which convert it into a magnet. Thus electromagnet can be formed due to the magnetic effect of current.

If we change in the direction of the current passing through the wire near to the magnetic needle:

physics magnetic effect of electric current oersted experiment oersted's experiment magnetic field due to a straight current carrying conductor

  1. position of the pole of the needle will change

  2. position of the pole of the needle will remain same

  3. change in position of the pole depends on the current intensity

  4. none of the above is correct

Show answer
Correct Option: A
Explanation:

When the direction of the current flowing through the wire is reversed, direction of the magnetic field, so produced, also changes its direction which results in changing the position of pole of needle kept near the wire.

A magnetic needle vibrates in a vertical plane parallel to the magnetic meridian about horizontal axis passing through its centre. The frequency is $\pi$. If the plane of oscillation turned about a vertical axis by ${90}^{o}$, the frequency of oscillation in vertical plane will be:

physics magnetic effect of electric current oersted experiment oersted's experiment magnetic field due to a straight current carrying conductor

  1. $\pi$

  2. zero

  3. less than $\pi$

  4. more than $\pi$

Show answer
Correct Option: C
Explanation:

Frequency $\pi=\dfrac{1}{2\pi}\sqrt{\dfrac{BM}I}$

On turning through angle $90°$, effective field is $V$ and $B>V$
$\implies $ new frequqncy $<\pi$ (less than $\pi)$

What did Oersted conclude from the experiment ?

physics magnetic effect of electric current oersted experiment oersted's experiment magnetic field due to a straight current carrying conductor

  1. The current carrying wire must be acting as a magnet for the compass needle to deflect.

  2. The current carrying wire gets heated up and causes the compass needle to deflect.

  3. The current carrying wire sets up air currents that makes the compass needle to deflect.

  4. None of the above

Show answer
Correct Option: A
Explanation:

The deflection of the compass needle, whenever there is current in the wire show that a current carrying wire produces a magnetic field around it, which is essentially saying the current carrying wire must be acting as a magnet.