Advertisements
Advertisements
State the factors that can increase the speed of rotation of the coil in a D.C. motor.
Concept: undefined >> undefined
State the energy change that takes’place in a D. C. motor.
Concept: undefined >> undefined
Advertisements
State the principle of a D. C. motor.
Concept: undefined >> undefined
State the position of armature coil relative to the direction of magnetic field, in a D. C. motor when the deflecting couple acting an the coil is maximum.
Concept: undefined >> undefined
State the position of armature coil relative to the direction of magnetic field, in a D. C. motor when the deflecting couple acting and the coil is minimum.
Concept: undefined >> undefined
What is dynomo (a.c. generator)? State the principle on which it works.
Concept: undefined >> undefined
The primary windings of a step-up transformer are usually made of thicker wire than the secondary. Explain.
Concept: undefined >> undefined
State important properties (or characteristics) of magnetic lines of force around a straight conductor.
Concept: undefined >> undefined
State the factors, on which depends the magnitude of the force acting on current carrying conductor, when it is kept in a magnetic field perpendicular to it.
Concept: undefined >> undefined
A current-carrying solenoid is suspended so as to freely rotate in a horizontal plane. State in what direction will it rest. Give a reason for your answer.
or
When a solenoid that is carrying current is freely suspended, it comes to rest in a particular direction. Why does this happen?
Concept: undefined >> undefined
What are the factors that govern the magnitude of force acting on a current carrying conductor which is freely suspended in a magnetic field?
Concept: undefined >> undefined
Point out three differences between an electromagnet and a bar (or permanent) magnet.
Concept: undefined >> undefined
State and explain Maxwell’s Cork Screw Rule.
Concept: undefined >> undefined
(i) A straight wire conductor passes vertically through a piece of cardboard sprinkled with iron filings. Copy the diagram and show the setting of iron filings when a current is passed through the wire in the upward direction and the cardboard is tapped gently. Draw arrows to represent the direction of the magnetic field lines.

(ii) Name the law which helped you to find the direction of the magnetic field lines.
Concept: undefined >> undefined
State the function of a split ring in D.C. motor.
Concept: undefined >> undefined
How does a magnetic field set up by a solenoid change when cross-sectional area of solenoid is increased?
Concept: undefined >> undefined
What is heat? What is the S. I. unit of heat?
Concept: undefined >> undefined
What are other units of heat? Name and define them.
Concept: undefined >> undefined
State the condition for the flow of heat energy from one body to another.
Concept: undefined >> undefined
What are the factors on which the quantity of heat given to a body depends?
Concept: undefined >> undefined
