English Medium कक्षा १० - CBSE Question Bank Solutions for Science

When is the force experienced by a current-carrying conductor placed in a magnetic field largest?

In a statement of Fleming's left-hand rule, what do the following represent?

(a) direction of centre finger.
(b) direction of forefinger.
(c) direction of thumb.

For Fleming's left-hand rule, write down the three things that are 90° to each other, and next to each one write down the finger or thumb that represents it.

 A current-carrying conductor is placed perpendicularly in a magnetic field. Name the rule which can be used to find the direction of force acting on the conductor.

State two ways to increase the force on a current-carrying conductor in a magnetic field.

 Name one device whose working depends on the force exerted on a current-carrying coil placed in a magnetic field. 

State Fleming's left-hand rule. Explain it with the help of labelled diagrams.

The force experienced by a current-carrying conductor placed in a magnetic field is the largest when the angle between the conductor and the magnetic field is: 

 45°
 60°
 90°
 180°

The force exerted on a current-carrying wire placed in a magnetic field is zero when the angle between the wire and the direction of magnetic field is: 

 45°
 60°
 90°
 180°

A current flows in a wire running between the S and N poles of a magnet lying horizontally as shown in Figure below: 

The force on the wire due to the magnet is directed: 

fron N to S
 from S to N
 vertically downwards
 vertically upwards

A horizontal wire carries a current as shown in Figure below between magnetic poles N and S: 

Is the direction of the force on the wire due to the magnet:

(a) in the direction the current
(b) vertically downwards
(c) opposite to the current direction
(d) vertically upwards 

In the simple electric motor of figure given below, the coil rotates anticlockwise as seen by the eye from the position X when current flows in the coil  

Is the current flowing clockwise or anticlockwise around the coil when viewed from above? 

If the current in a wire is flowing in the vertically downward direction and a magnetic field is applied from west to east, what is the direction of force in the wire?

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

What is the force on a current-carrying wire that is parallel to a magnetic field? Give reason for your answer. 

 force experienced by a current-carrying straight conductor placed in a magnetic field which is perpendicular to it. 

Two coils A and B of insulated wire are kept close to each other. Coil A is connected to a galvanometer while coil B is connected to a battery through a key. What would happen if: 

a current is passed through coil B by plugging the key?  

Explain your answer mentioning the name of the phenomenon involved.

Two coils A and B of insulated wire are kept close to each other. Coil A is connected to a galvanometer while coil B is connected to a battery through a key. What would happen if: 

the current is stopped by removing the plug from the key? 

Explain your answer mentioning the name of the phenomenon involved. 

Why is photosynthesis considered an endothermic reaction?

What are anti-oxidants? Why are they added to fat and oil containing foods?