Advertisements
Advertisements
प्रश्न
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
Advertisements
उत्तर
(a) `1/(RC)`
(b) `R/L`
(c) `1/sqrt(LC)`
The time constant of the RC circuit is given by
`tau=RC`
On taking the reciprocal of the above relation, we get
`f_1=1/(RC).............(1)`
f1 will have the dimensions of the frequency.
The time constant of the LR circuit is given by
`tau=L/R`
On taking the reciprocal of the above relation, we get
`f_2=R/L............(2)`
f2 will have the dimensions of the frequency.
On multiplying eq. (1) and (2), we get
`f_1f_2=1/(LC)`
`rArrsqrt(f_1f_2)=1/sqrt(LC)`
Thus, `sqrt(f_1f_2)` will have the dimensions of the frequency.
APPEARS IN
संबंधित प्रश्न
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.
Name a common device that uses electromagnets.
An emf of 2V is induced in a coil when the current in it is changed from 0A to 10A in 0·40 sec. Find the coefficient of self-inductance of the coil.
Explain why, the core of an electromagnet should be of soft iron and not of steel.
Write some of the important uses of electromagnets.
The most suitable material for making the core of an electromagnet is:
(a) soft iron
(b) brass
(c) aluminium
(d) steel
What condition is necessary for the production of current by electromagnetic induction?
An induced current is produced when a magnet is moved into a coil. The magnitude of induced current does not depend on:
(a) the speed with which the magnet is moved
(b) the number of turns of the coil
(c) the resistivity of the wire of the coil
(d) the strength of the magnet
In which of the following case does the electromagnetic induction occur?
A magnet is moved through a loop of wire .
Answer the following:
State the principles of the electric motor and electric generator.
Draw a labelled diagram to make an electromagnet from a soft iron bar. Mark the polarity at its ends in your diagram. What precaution would you observe while making it?
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.
State Fleming’s right-hand rule.
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 generator has an e.m.f. of 440 Volt and internal resistance of 4000 hm. Its terminals are connected to a load of 4000 ohm. The voltage across the load is ______.
Which of the following phenomena makes use of electromagnetic induction?
The charge will flow through a galvanometer of resistance 200Ω connected to a 400Ω circular coil of 1000 turns wound on a wooden stick 20 mm in diameter, if a magnetic field B = 0.012 T parallel to the axis of the stick decreased suddenly to zero, is near ______.
Which type of force is experienced by a moving charge in a magnetic field?
When an electric current is passed through a wire or a coil, a magnetic field is produced. Is the reverse phenomenon possible i.e, can a magnetic field produce an electric current? Explain with the help of an appropriate example.
