Advertisements
Advertisements
प्रश्न
Write Fleming’s right hand thumb rule with the help of diagram.
Advertisements
उत्तर
If a current-carrying straight conductor is held in our right hand such that the thumb points towards the direction of the current, then the curled fingers around the conductor will give the direction of the magnetic field.
APPEARS IN
संबंधित प्रश्न
A solenoid of length 1.5 m and 4 cm in diameter possesses 10 turns per metre. A current of 5 A is flowing through it. The magnetic induction at a point inside the solenoid along the axis is ............................. .
(μ0 = 4π × 10-7 Wb/Am)
- π × 10-5 T
- 2π × 10-5 T
- 3π × 10-5 T
- 4π × 10-5 T
When a bar magnet is pushed towards (or away) from the coil connected to a galvanometer, the pointer in the galvanometer deflects. Identify the phenomenon causing this deflection and write the factors on which the amount and direction of the deflection depends. State the laws describing this phenomenon.
Prove theoretically (electromagnetic induction) `e = (dphi)/(dt)`
Name a common device that uses electromagnets.
The most suitable material for making the core of an electromagnet is:
(a) soft iron
(b) brass
(c) aluminium
(d) steel
When current is 'switched on' and 'switched off' in a coil, a current is induced in another coil kept near it. What is this phenomenon known as?
What do you understand by the term "electromagnetic induction"? Explain with the help of a diagram.
In which of the following case does the electromagnetic induction occur?
The current is stopped in a wire held near a loop of wire .
Name and state the law which determines the direction of induced current.
or
State Fleming’s right-hand rule.
Consider the energy density in a solenoid at its centre and that near its ends. Which of the two is greater?
A conducting square loop of side l and resistance R moves in its plane with a uniform velocity v perpendicular to one of its sides. A uniform and constant magnetic field Bexists along the perpendicular to the plane of the loop as shown in figure. The current induced in the loop is _____________ .
A conducting rod is moved with a constant velocity v in a magnetic field. A potential difference appears across the two ends _____________ .
L, C and R represent the physical quantities inductance, capacitance and resistance respectively. Which of the following combinations have dimensions of frequency?
(a) `1/(RC)`
(b) `R/L`
(c) `1/sqrt(LC)`
(d) C/L
What is an electromagnet? What do you know about the simplest form of an electromagnet?
You have been provided with a solenoid AB.
(i) What is the polarity at end A?
(ii) Give one advantage of an electromagnet over a permanent magnet.
The energy stored in a 50 mH inductor carrying a current of 4 A is ______
Using Ampere's law, obtain an expression for the magnetic induction near a current-carrying straight infinitely long wire.
The right-hand thumb rule is also called _______ rule.
Fleming's left hand rule : electric current : : Fleming's right hand rule : _______
State Lenz’s law.
Establish the fact that the relative motion between the coil and the magnet induces an emf in the coil of a closed circuit.
Give an illustration of determining direction of induced current by using Lenz’s law.
Show that Lenz’s law is in accordance with the law of conservation of energy.
The magnetic flux passing through a coil perpendicular to its plane is a function of time and is given by OB = (2t3 + 4t2 + 8t + 8) Wb. If the resistance of the coil is 5 Ω, determine the induced current through the coil at a time t = 3 second.
An induced current of 2.5 mA flows through a single conductor of resistance 100 Ω. Find out the rate at which the magnetic flux is cut by the conductor.
A cylindrical bar magnet (A) and similar unmagnetized cylindrical iron bar (B) are dropped through metallic pipe. The time taken to come down by ____________.
The condition for the praenomen of electromagnetic induction is that there must be a relative motion between ____________.
Name some equipment that uses electromagnetism for functioning.
Induced current flows through a coil ______.
A galvanometer is an instrument that can detect the presence of a current in a circuit.
A coil of one turn is made of a wire of certain length and then from the same length, a coil of two turns is made. If the same current is passed in both the cases, then the ratio of the magnetic inductions at their centres will be:
A conductor of length 50 cm carrying a current of 5 A is placed perpendicular to a magnetic field of induction 2×10 -3T. Find the force on the conductor.
Which of the following phenomena makes use of electromagnetic induction?
A rectangular, a square, a circular and an elliptical loop, all in the (x - y) plane, are moving out of a uniform magnetic field with a constant velocity `vecv = vhati`. The magnetic field is directed along the negative z-axis direction. The induced emf, during the passage of these loops, out of the field region, will not remain constant for ______.
AB is a coil of copper wire having a large number of turns. The ends of the coil are connected with a galvanometer as shown. When the north pole of a strong bar magnet is moved towards end B of the coil, a deflection is observed in the galvanometer.
- State the reason for using galvanometer in the activity and why does its needle deflects momentarily when magnet is moved towards the coil.
- What would be observed in the galvanometer in a situation when the coil and the bar magnet both move with the same speed in the same direction? Justify your answer.
- State the conclusion that can be drawn from this activity.
Will there be any change in the momentary deflection in the galvanometer if number of turns in the coil is increased and a more stronger magnet is moved towards the coil?
OR
What is electromagnetic induction? What is observed in the galvanometer when a strong bar magnet is held stationary near one end of a coil of large number of turns? Justify your answer.
