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Multiple choice physics electromagnetic forces magnetic field due to a circular current carrying conductor magnetic field produced in a circular loop oersted experiment oersted's experiment magnetic field due to a straight current carrying conductor

Which of the following observations are true for Hans Oersteds experiment?
a. When current passes through the wire the compass needle comes to rest in a direction along the Earths magnetic field.
b. When placed just above the wire, North Pole of the compass needle deflects towards the east when current is passes from A to B.
c. When placed just below the wire, North Pole of the compass needle deflects towards the east when current is passes from B to A i.e. on reversing the direction of current

  1. a and c

  2. a and b

  3. b and c

  4. All of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Oersted conducted an experiment to study the magnetic effect of electric current. In this experiment he observed the deflections of a compass needle placed in close proximity of an electric wire carrying current. He observed that in the absence of current the needle came to rest in Earths North-south direction under the influence of Earths magnetic field. However, when the needle was kept below the wire and current was passed from A to B the north pole of the needle deflected towards the west and on reversing the direction of the current from B to A, it deflected towards the east. Similarly, when the needle was kept above the wire and current was passed from A to B the north pole of the needle deflected towards the east and on reversing the direction of the current from B to A, it deflected towards the west. This indicates that the direction of the magnetic field depends on the direction of current.

Multiple choice physics electromagnetic forces magnetic field due to a circular current carrying conductor magnetic field produced in a circular loop oersted experiment oersted's experiment magnetic field due to a straight current carrying conductor

When current passes through the circuit a compass needle rests in which direction (with respect to the Earth)?

  1. South-north

  2. North-south

  3. East-west

  4. West-east
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The earth acts like a huge magnet. Thus in the absence of electric current a compass needle always comes to rest in Earths North-south direction. However, when current passes through the circuit the needle comes to rests in the direction opposite to the magnetic field of Earth i.e. South-North direction.

Multiple choice physics electromagnetic forces magnetic field due to a circular current carrying conductor magnetic field produced in a circular loop oersted experiment oersted's experiment magnetic field due to a straight current carrying conductor

State whether True or False :

If electric current is passed through metal body then it behaves as magnet.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

If electric current is passed through metal body then it behaves as magnet. passing an electric current through iron does not produce a magnet. But if you pass a direct current through a coil wound around the piece of iron, you will magnetize it. Passing a direct electric current through the same coil with no iron inside the coil will still produce a magnetic field that behaves just like a magnet. Similarly, passing a direct current through a coil around a piece of Bismuth will create the same magnetic field which behaves just like a magnet.

Multiple choice physics electromagnetic forces magnetic field due to a circular current carrying conductor magnetic field produced in a circular loop oersted experiment oersted's experiment magnetic field due to a straight current carrying conductor

Who first discovered the relationship between electricity and magnetism?

  1. Faraday

  2. Newton

  3. Maxwell

  4. Oersted
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Oersted discovered the relationship between electricity and magnetism.

Multiple choice physics electromagnetic forces magnetic field due to a circular current carrying conductor magnetic field produced in a circular loop oersted experiment oersted's experiment magnetic field due to a straight current carrying conductor

Chose the correct statement from the following:

  1. Electric current is a scalar quantity

  2. Charge carries in metals are ions

  3. The area of current- time graph gives charge

  4. A charge in motion produces both electric and magnetic field
Reveal answer Fill a bubble to check yourself
A,C,D Correct answer
Explanation
$(i)$ Option- $A$ is correct, since current has no directional attribute to it, it is a scalar quantity.
$(ii)$ Option- $B$ is correct, Charge carries in metal are free electrons whereas in electrolytic solution they are ions
$(iii)$ Option- $C$ is correct because $i=\dfrac{da}{dt}\Rightarrow =i dt \Rightarrow a=\displaystyle \int{i. dt}$
$\displaystyle \int{i. dt}$ is the area under current-time graph
$(iv)$ Option- $D$ is correct, charge in motion produces current which in term produces magnetic field.
Multiple choice physics electromagnetic forces magnetic field due to a circular current carrying conductor magnetic field produced in a circular loop oersted experiment oersted's experiment magnetic field due to a straight current carrying conductor

Two long parallel wires A and B separated by a distance d, carry currents $i _1$ and $i _2$ respectively in the same direction. Write the following steps in a sequential order to find the magnitude of the resultant magnetic field at a point 'P', which is between the wires and is a distance '$x$' from the wire A.
(All the physical quantities are measured in SI units)
(a) Note the given values of $i _1, i _2$, $d$ and $x$.
(b) Write the formula to find the magnetic field due to a long straight current carrying wire i.e. $\displaystyle B=\frac{\mu _0 i}{2 \pi r}$
(c) Find the directions of the magnetic field at 'P' due to two wires A and B, using right hand thumb rule.
(d) Determine the magnetic field at P due to wire A, using $B _1 \displaystyle = \frac{\mu _0 i _1}{2 \pi x}$
(e) If the directions of magnetic field are same, then the resultant magnitude is equal to the sum of $B _1$ and $B _2$.
(f) Determine the magnetic field $B _2$ due to wire B at point P, ie. $B _2 = \displaystyle \frac{\mu _o i _2}{2 \pi (d-x)}$
(g) If the directions of magnetic fields are opposite to each other, then the resultant magnitude is equal to the difference of $B _1$ and $B _2$.

  1. $d f c e g b a$

  2. $c d f e g b a$

  3. $a c b d f e g$

  4. $a b d f c e g$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The logical sequence for calculating the resultant magnetic field is: identify values, write the formula, determine individual fields (B1 and B2), determine directions, and then sum or subtract based on those directions.

Multiple choice physics electromagnetic forces magnetic field due to a circular current carrying conductor magnetic field produced in a circular loop oersted experiment oersted's experiment magnetic field due to a straight current carrying conductor

Consider a region where both uniform electric and magnetic fields E and B are present both along the z-axis. A positively charged particle of charge and mass is released from the origin with an initial velocity ${{\text{V}} _e}\hat i$. Which of the following option(s) are correct?

  1. (A)The y coordinate of the particle at time ${\text{t}} = \frac{{\pi {\text{M}}}}{{{\text{qB}}}}{\text{ is}}\frac{{ - 2{\text{mv}}}}{{{\text{qB}}}}$

  2. (B)The distance between two consecutive point on the z-axis where the particle touches the Z-axis is an odd multiple of a constant distance.

  3. (C)The distance between two consecutive point on the z-axis where the particle touches the Z-axis is an even multiple of a constant distance.

  4. (D)The time after which the particle touches the z-axis is $\frac{{2\pi {\text{m}}}}{{{\text{qB}}}}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This is a classic problem of a charged particle in crossed electric and magnetic fields. The particle undergoes cycloidal motion. The y-coordinate calculation at the specified time is a standard derivation for this motion.

Multiple choice physics reflection of light and shadow regular and irregular reflection regular and diffused reflection laws of reflection

You are able to see in shaded areas, such as under a tree, because light has undergone:

  1. refraction

  2. incident bending

  3. a change in speed

  4. diffused reflection
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In a diffused or irregular reflection, parallel rays of light, after striking a rough and curved surface, get reflected irregularly.