English Medium कक्षा १० - CBSE Question Bank Solutions for Science

Fill in the following blank with suitable words: 

The magnetic effect of a coil can be increased by increasing the number of ........... increasing the ........... or inserting an ........... core.

Fill in the following blank with suitable words:

 If a coil is viewed from one end and the current flows in an anticlockwise direction, then this end is a ........... pole.

Fill in the following blank with suitable words: 

 If a coil is viewed from one end, and the current flows in a clockwise direction, then this end is a ........... pole.

Describe some experiment to show that the magnetic field is associated with an electric current. 

What is Maxwell's corkscrew rule? For what purpose is if used?

If the direction of electric current in a solenoid when viewed from a particular end is anticlockwise, then this end of solenoid will be:

(a) west pole
(b) south pole
(c) north pole
(d) east pole

The magnetic effect of current was discovered by:

(a) Maxwell
(b) Fleming
(c) Oersted
(d) Faraday

For the coil in the diagram below, when the switch is pressed:

(a) what is the polarity of end A?
(b) which way will the compass point then?    

The direction of current flowing in the coil of an electromagnet at its two ends X and Y are as shown below:  

 What is the polarity of end X?

What is the polarity of end Y?   

Name and state the rule which you have used to determine the polarities. 

Name one device which works on the magnetic effect of current.

 What device reverses the current?

Which way does the wire in the diagram below  tend to move? 

When the switch S is closed in the figure given below, the pointer of the galvanometer moves to the right.  

If S is kept closed, will the pointer:

(a) return to zero?
(b) stay over on the right?
(c) move to the left and stay there
(d) move to and fro until S is opened

The north pole of a long bar magnet was pushed slowly into a short solenoid connected to a galvanometer. The magnet was held stationary for a few seconds with the north pole in the middle of the solenoid and then withdrawn rapidly. The maximum deflection of the galvanometer was observed when the magnet was ______.

A coil is connected to a galvanometer. When the N-pole of magnet is pushed into the coil, the galvanometer deflected to the right. What deflection, if any, is observed when:  

 the N-pole is removed?

A coil is connected to a galvanometer. When the N-pole of magnet is pushed into the coil, the galvanometer deflected to the right. What deflection, if any, is observed when: 

 the S-pole is inserted?

A coil is connected to a galvanometer. When the N-pole of magnet is pushed into the coil, the galvanometer deflected to the right. What deflection, if any, is observed when: 

the magnet is a rest in the coil? 

If fuse of 250 mA, 500 mA, 1 A, 5 A and 10 A were available, which one would be the most suitable for protecting an amplifier rated at 240 V, 180 W?  

How should the electric lamps in a building be connected so that the switching on or off in a room has no effect on other lamps in the same building?

Why are metals called electropositive elements whereas non-metals are called electronegative elements?