Electromagnetic Induction - Short Question and Answer

Electromagnetic Induction - Short Question and Answer Points : electromagnetic induction short question and answer Q. 1. Why is idea of inductance important? Ans. Inductance concept is very useful as it enables us to express an induced e.m.f. directly in terms of changing current, rather than have to go through intermediate step of calculating flux caused by the current, and then apply Faraday’s laws. Q. 2. What is source of name electromagnetic induction? Ans. Thus called as electricity is produced as of magnetism (i.e. electromagnetic) and that there is no physical connection (induction) among the magnetic field and the conductor. Q. 3. Why do we use air-cored transformers for high rate applications? Ans. At high frequencies, iron-core transformers contain disadvantage of high hysteresis and eddy-current losses. Also, iron core becomes less effective as a magnetic circuit as rate reaches high values as the flux penetrates to a gradually lesser extent into core. Since air does not show hysteresis and eddy current effects, use of air-core transformers is familiar at radio frequencies found in electronics and communication engineering.

Magnetic Circuits - Short Question and Answer

Magnetic Circuits - Short Question and Answer Points : magnetic circuits short question and answer Q. 1. Does a magnetic circuit consume energy? Ans. Though energy is required in order to set up a magnetic flux, no energy is necessary to continue it. This supplied energy is store in magnetic field. While magnetic field collapses (by opening circuit switch), the stored magnetic energy is return to circuit Though, energy is consumed in an electric circuit. Q. 2. Why does leakage occur in a magnetic circuit? Ans. In a practical magnetic circuit, large amount of flux is confine to intended path (i.e. iron path and air gap path in magnetic circuit) but a small amount of flux inevitably Leaks through surrounding air. This stray flux is termed as leakage flux. Leakage flux is useless or even harmful in an electrical machine.

Magnetism and Electromagnetism - Short Question and Answer

Magnetism and Electromagnetism - Short Question and Answer Points : magnetism and electromagnetism - short question and answer Q. 1. An electron travelling south to north posses through an electric field directed from west to east. In which direction should a magnetic field be applied so that electron goes undeflected? Ans : The electric force on a charge is parallel to the electric field. In the present case, the electric force on the electron is towards west. In order to balance it, the magnetic force on the electron should be directed towards east. By right-hand rule, the magnetic field should act vertically downward. Q. 2. A circular loop of radius 0.1 m carries a current JA and is placed in a uniform magnetic field of 0.5 T The magnetic field is perpendicular to the plane of the loop. What is the force experienced by the loop? Ans : A current carrying loop is equivalent to a magnetic dipole. A magnetic dipole does not experience any force in a uniform magnetic field. Therefore, this current carrying loop will not experience any net force.

Capacitance - Short Question and Answer

Capacitance - Short Question and Answer Points : capacitance - short question and answer Q. 1. Two spheres of different capacitances are electric to different potentials. They are then connected through a wire. Will total power increase, decrease or stay the same? Ans : The two spheres are at dissimilar potentials. Then, when they are attached through a wire, there will be redistribution of charge that is., flow of charge through wire) till the two spheres reach the similar potential. Due to flow of charge through connecting wire, A few energy will be lost as heat. Therefore, total energy after connecting the spheres will decrease.

Electrostatics - Short Question and Answer

Electrostatics - Short Question and Answer Points : Electrostatics-Short Question and Answer Q. 1. Does electric potential enhance or decrease along an electric line of force? Ans. The electric field amount acts in direction of electric line of force. We know that, E = - dVI dr. This means that in direction of electric field amount, potential decreases. It is similar thing as potential decreases along an electric line of force. Q. 2. While ordinary rubber is insulator, the rubber tyres of air craft are made slightly conducting. Why? Ans. During the take off and landing, the friction among tyres and the nm-way causes electrification of tyres. lithe tyres are non-conducting, extreme charge will accumulate on the tyres which might cause sparking. If material of the tyres is faintly conducting, the accumulate charge can flow to earth, therefore eliminting any hazard of fire.

Electrical Work Power and Energy - Short Question and Answer

Electrical Work Power and Energy - Short Question and Answer Points : electrical work power and energy short question and answer Q. 1. The element of heater is very hot as the wires carrying current are cold. Why? Ans : Element of heater is made of nichrome as wires carrying current are prepared of aluminium/copper. The resistance of nichrome is extremely high as compare to that of copper/aluminium. While it is a series circuit, heat produced (H = I² Rt) depends only upon resistance of conductor in this case. Thus the element of heater is extremely hot due to its high resistance as the lead wires are cold due to their short resistance.

Network Theorems - Short Question and Answer

Network Theorems - Short Question and Answer Points : network theorems short question and answer Q 1. What are the applications of current sources? Ans : Current sources have some applications:
(i) Current sources can too be use to signify equipment for example current-regulated power supplies.
These supplies give a stable current over several limited range of load resistance.
(ii) They can use in definite network study procedures.
(iii) They are use to signify definite devices that show a stable current behavior. Transistors are exemplar of such devices.