Advertisements
Advertisements
प्रश्न
What is an electroscope? Describe the different stages of charging a gold leaf electroscope negatively with the help of a diagram.
उत्तर
An electroscope is a device used to detect the presence of charge and the nature of a charge on the body.
The four stages of the charging a gold leaf electroscope by induction are :
(i) Bring a positively charged rod near the cap of an electroscope. The cap will acquire a negative charge on it by induction. The leaves will diverge
(ii) Earth the electroscope by touching the cap will finger.
(iii) Remove the finger and keep the positively charged rod as such.
(iv) Now, take away the rod. The leaves will diverge because of charges induced by induction.
APPEARS IN
संबंधित प्रश्न
Why is soft iron used as the core of the electromagnet in an electric bell?
Electromagnets are made up of :
How is an electromagnet made? Name two factors on which the strength of magnetic field of the electromagnet depends.
The following figure shows a coil wound around a soft iron bar XY.
- State the polarity at the ends X and Y as the switch is pressed.
- Suggest one way of increasing the strength of electromagnet so formed.
A coil of insulated copper wire is wound around a piece of soft iron and current is passed in the coil from a battery. What name is given to the device so obtained? Give one use of the device mentioned by you.
State two ways through which the strength of an electromagnet can be increased.
Name one device that uses an electromagnet.
State two differences between an electromagnet and a permanent magnet.
Why is soft iron used as the core of the electromagnet in an electric bell?
Explain the working of the following device.
Magnetic levitation trains.