Induced Current and Induced emf

Q. Magnetic flux through a closed surface is zero because the field lines entering the surface is equal to the field lines leaving the surface. So cant magnetic flux through a plain surface be zero?Number of field lines entering the plane surface can also be equal to the field lines leaving the plain surface.

Q.

What are the characteristics of the Colombian force?

Q.

What factors determine how much voltage is induced?

Q.

Can an electric field pass through an insulator?

Q.

When will the induced current be highest based on the coil motion?

Q.

What is the total number of magnetic field lines passing through an area called?

1. ​​​​​​Magnetic flux
2. ​​​​​​Magnetic flux density
3. ​​​​​E.M.F
4. Voltage

Q.

Is the electrostatic force always attractive?

Q.

Compare the thickness of secondary coil of a step-up transformer with the primary coil

1. Secondary coil is thinner as compared to its primary coil so that the secondary coil has smaller resistance than primary

2. Secondary coil has same thickness as the primary coil

3. Secondary coil is thinner as compared to its primary coil so that the secondary coil has greater resistance than primary

4. Primary coil is thinner as compared to its Secondary coil so that the secondary coil has greater resistance than primary

5. The thickness depends on the material of the coil and the strength of the currents in the two coils

Q.

Why does a current carrying conductor behave like a magnet?

What happens at the microscopic level?

Q. Induced emf can be produced by:

1. a moving magnet.
2. a steady current carrying moving wire.
3. an alternating current carrying wire at rest.
4. a steady current carrying wire at rest.

Q. Which of the following statement(s) is/are correct regarding magnetic field lines?

1. The direction of the magnetic field is tangent to the field line at any point in space.
2. Magnetic field lines are closed curves.
3. Magnetic field lines represent zero field strength if they are parallel and equidistant.
4. The degree of closeness of the field lines at a point is the relative strength of magnetic field strength at that point.

Q. { Two coils }A and }B have mutual inductance }2×10^{-2} henry. }}{ If the current in the primary is }i=5\operatorname{sin}(10π t) then the }}{ maximum value of e.m.f. induced in coil }B is

Q.

The only way to induce current in a solenoid is by moving a magnet near the solenoid.

1. False

2. True

Q.

SI units of current is:

1. Ohm

2. Ampere

3. Joule

4. Volt

Q.

Which among the following is the condition for electromagnetic induction to take place?

1. There must be a relative motion between the galvanometer and the magnet.

2. There must be a relative motion between the coil and a magnet.

3. There must be a relative motion between the galvanometer and the generator.

4. There must be a relative motion between the coil and the galvanometer.

Q.

When there is a moving magnet in the vicinity of a coil, there will be electric current flowing through the coil.

1. True

2. False

Q.

Name two appliances that work on the magnetic effect of current.

Q. Magnetic flux density is maximum at the __________ of a magnet.

1. poles
2. surface
3. centre
4. edges

Q.

Can Mutual inductance be negative?

Q. A steady current is flowing in a cylindrical conductor.Is there any electric field within the conductor?

Q. Faraday's first law

Q. When the switch is turned ON, what will happen to the bulb?

1. Bulb will glow continuously
2. Bulb will not glow
3. Bulb will blink
4. Bulb will glow once and then get switched off

Q.

Which among the following is/are the way to increase the strength of the current through the given solenoid?

1. Increasing the number of turns of the coil.

2. Moving the magnet with greater speed towards or away from the solenoid.

3. Reducing the strength of permanent magent used.

4. Reducing the number of turns in the coil.

Q.

Why solenoid is used to magnetise a piece of magnetic materials, like soft iron, when placed inside the coil?

1. Due to its uniform magnetic field

2. Due to its shape

3. Due to its strong magnetic field

4. All of the above

Q.

The voltage that is induced by the motion of a conductor across a magnetic field is called _____.

1. electromotive force (emf)

2. electromagnetic force

3. electrostatic force

4. gravitational force

Q.

Choose the correct statement/statements from the following options regarding the magnetic field lines of an electromagnet.

1. The magnetic field lines do not form closed lines.

2. The magnetic field lines are closed lines.

3. If magnetic field lines are parallel and equidistant, they represent zero field strength.

4. Magnetic field lines do not intersect each other.

Q.

Can the polarity of magnetic field produced by a current carrying solenoid can be reversed by reversing the ends of the solenoid ie, by connecting upside down?

Q. How do you measure the relative strength of a magnetic field of an electromagnetic coil?

1. Calculate the density of iron filings at the edges
2. Calculate the size of the magnetic field produced
3. Use a multimeter to calculate the current flowing through the coil
4. Use a voltmeter to find the current flowing through the coil

Q. What causes a current carrying wire to behave as a magnet ?

Q.

Is the magnetic field inside a current-carrying solenoid constant at all points?