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# arrow_back CBSE Class - 10 Science Online Practice Tests

### Question 1

When the direction of current in a conductor is reversed, then the deflection of the needle of the compass placed near a current carrying conductor ____.
A) does not change
B) reverses its direction
C) increases in the same direction
D) decreases in the same direction

### Question 2

When current in a conductor is switched off, the magnetic needle placed near this conductor ____.
A) gets deflected in the reverse direction
B) does not change its position
C) gets back to its initial position
D) will be perpendicular to the length of the conductor

### Question 3

The strength of magnetic field produced by a current carrying solenoid depends upon the ____.
A) current passing through the solenoid
B) direction of the current
C) shape of the solenoid
D) polarity of the solenoid

### Question 4

The strength of magnetic field produced by a current carrying solenoid does not depend upon the ____.
A) number of turns per unit length of the solenoid
B) direction of current
C) nature of the core present inside the solenoid
D) strength of the current

### Question 5

When two bar magnets are kept in contact with their like poles placed together for a long time, they get demagnetised due to the induction of like poles on each other.
A) True
B) False

### Question 6

Polarity of an electromagnet gets reversed by ____.
A) decreasing the number of turns
B) increasing the number of turns
C) reversing the direction of current
D) switching of current

### Question 7

An electromagnet can be demagnetized by ____.
A) keeping poles together
B) rubbing it
C) switching off the current
D) changing the direction of current

### Question 8

In an electric bell, we use a ____ because the magnetism developed in the rod is ____.
A) soft iron rod, permanent
B) steel rod, permanent
C) soft iron rod, temporary
D) steel rod, temporary

### Question 9

When a steel rod is used in place of a soft iron rod in an electric bell, the ____.
A) frequency of the sound produced is more
B) intensity of the sound produced is more
C) bell does not ring continuously
D) bell rings using less power

### Question 10

Electric motor works on the principle of torque experienced by a current carrying coil in a magnetic field.
A) True
B) False