# Recent questions tagged field

Briefly describe the electric field of a static charge.

Field intensity formula

Energy stored in electrostatic field of capacitance formula

What arc the errors occurring in measuring devices due to stray magnetic field and temp '? Explain how to compensate them.

Define junction field effect transistor (JFET) and give an example.

Derive an expression for energy stored in a magnetic field .

Give the relation between magnetic field strength, magnetic flux density and permeability.

Define magnetic field strength and state its unit.

In a synchronous machine, if the field flux axis ahead of the armature field axis in the direction of rotation, the machine is operating as  (1) synchronous motor (2) synchronous generator (3) asynchronous motor (4) asynchronous generator

The ability of materials to become polarized under an applied electric field is called _______ A) Ferroelectricity B) Paraelectricity C) Polectricity D) None of these

Which of the following laws relates the magnetic field to the magnitude, direction, length, and proximity of the electric current? A) Lenz’s law B) Faraday’s law C) Biot–Savart law D) None of these

The electric field inside a hollow conducting sphere ________ A) Depends on the diameter of the sphere  B) Varies according to the direction of earth’s magnetic poles C) Is zero  D) None of these

Which of the following statements is not characteristic of a static magnetic field? (A) It is solenoidal. (B) It is conservative. (C) It has no sinks or sources. (D) Flux lines are always closed.

It is possible to increase the field flux and, at the same time, increase the speed of a d.c. motor provided its .......... is held constant.

A field of force can exist only between?

MOSFET uses the electric field of?

An electric motor in which both stator field and rotor rotates with same speed is called?

If the field of synchronous motor is under excited, power factor will be?

Is electric potential zero when electric field is zero?

What is the direction of the induced electric field?

Can the electric field between two positive charges be zero?

What is the direction of the electric field?

How can a magnetic field be used to generate an electric current?