Question
Write any three characteristics, a ferromagnetic substance should possess if it is to be used to make a permanent magnet. Give one example of such a material.
✓
Answer
Characteristics for permanent magnet.
- High permeability.
- High retentivity.
- High coercivity.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
A transformer is designed to convert an AC voltage of 220V to an AC voltage of 12V. If the input terminals are connected to a DC voltage of 220V, the transformer usually burns. Explain.
Describe briefly, with the help of a circuit diagram, how a potentiometer is used to determine the internal resistance of a cell.
If you jump barefooted on a hard surface, your legs get injured. But they are not injured if you jump on a soft surface like sand or pillow. Explain.
A point source emitting 628 lumen of luminous flux uniformly in all directions is placed at the origin. Calculate the illuminance on a small area placed at (1.0m, 0, 0) in such a way that the normal to the area makes an angle of 37º with the X-axis.
The radius of a spherical conductor shell is $R$ and the charge on it is $Q$. Compare the potential at a distance 2 R from the centre of the sphere with the potential at a distance $R / 2$.
→In half-wave rectification, what is the output frequency if the input frequency is 50 Hz. What is the output frequency of a full-wave rectifier for the same input frequency.
Show diagrammatically when is magnetic flux taken as:
- Positive.
- Negative.
Two monochromatic rays of light are incident normally on the face AB of an isosceles right-angled prism ABC. The refractive indices of the glass prism for the two rays ‘1’ and ‘2’ are respectively 1.3 and 1.5 Trace the path of these rays after entering through the prism.
A source of sound with adjustable frequency produces 2 beats per second with a tuning fork when its frequency is either 476Hz or 480Hz. What is the frequency of the tuning fork?
Explain the process of thermonuclear fusion as a source of energy in the Sun.