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
Name one device that uses an electromagnet.
The strength of the electromagnet can be increased by
Name the material used for preparing an electromagnet.
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.
State two advantages of an electromagnet over a permanent magnet.
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, why steel is used in preference to soft iron for making permanent magnets while soft iron is used in preference to steel for making electromagnets.
Assertion (A): When 2 long parallel wires, hanging freely are connected in parallel to a battery, they come closer to each other.
Reason (R): Wires carrying current in opposite directions repel each other.
Explain the working of the following device.
Magnetic levitation trains.