Courses

# Test : Magnetic Effects Of Current 4

## 25 Questions MCQ Test NCERT Textbooks (Class 6 to Class 12) | Test : Magnetic Effects Of Current 4

Description
This mock test of Test : Magnetic Effects Of Current 4 for UPSC helps you for every UPSC entrance exam. This contains 25 Multiple Choice Questions for UPSC Test : Magnetic Effects Of Current 4 (mcq) to study with solutions a complete question bank. The solved questions answers in this Test : Magnetic Effects Of Current 4 quiz give you a good mix of easy questions and tough questions. UPSC students definitely take this Test : Magnetic Effects Of Current 4 exercise for a better result in the exam. You can find other Test : Magnetic Effects Of Current 4 extra questions, long questions & short questions for UPSC on EduRev as well by searching above.
QUESTION: 1

### The use of fuses in electric power-lines is :

Solution:

A fuse is used to break the circuit,in order to protect the electrical appliances from damage. In case of overcurrent a fuse melts and breaks the circuit and stops the current flowing through the components. A fuse is made up of a thin material which has a low melting point.

QUESTION: 2

Solution:
QUESTION: 3

### When a fuse is rated at 8 A, it means :

Solution:

When a fuse is rated 8A, it means- It will not work if current is less than 8A. It has a resistance of 8 ohm.

QUESTION: 4

According to International Convention of colour coding of wires used in household electrical circuits :

Solution:

According to international color coding system in Old colors red is live ( or phase) black is neutral, green/ yellow is earth.

QUESTION: 5

The magnetic field lines inside a current carrying solenoid are :

Solution:

The field lines inside the solenoid are in the form of parallel straight lines. This indicates that the magnetic field is the same at all points inside the solenoid. That is, the field is uniform inside the solenoid.

QUESTION: 6

Potential difference between a live wire and the neutral wire is :

Solution:
QUESTION: 7

Which of the following statements is incorrect regarding magnetic field lines :

Solution:
QUESTION: 8

Magnetic field lines determine :

Solution:
QUESTION: 9

The magnetic field near a long straight wire is described by :

Solution:
QUESTION: 10

The phenomenon of electromagnetic induction is :

Solution:
QUESTION: 11

Potential difference between a live wire and the neutral wire is :

Solution:
QUESTION: 12

A rectangular coil of copper wires is rotated in a magnetic field. The direction of the induced current changes once in each :

Solution:
QUESTION: 13

Magnetic field inside a long solenoid carrying current is :

Solution:

The field lines inside the solenoid are in the form of parallel straight lines. For a solenoid, the field has to be uniform as a function of position along the axis, since every point along the length is the same as every other point. This indicates that the magnetic field is uniform inside the solenoid.
Hence magnetic field is the same at all points inside the solenoid.

QUESTION: 14

At the time of short circuit, the current in the circuit :

Solution:
QUESTION: 15

The frequency of direct current is :

Solution:
QUESTION: 16

The frequency of household supply of a.c. in India is :

Solution:
QUESTION: 17

The most important safety device method used for protecting electrical appliances from short circuiting or overloading is :

Solution:
QUESTION: 18

Current flowing in conductor A is 2A and current flowing in conductor B is 4A. The ratio of magnetic field produced around conductor A to the magnetic field produced around conductor B at a distance 10 cm from both the conductors is:

Solution:

Because both of them have current flowing through them in equal ratio. i1: i2 = mag1: mag2

QUESTION: 19

Current flowing in conductors A and B is same, what is the ratio of the magnetic field produced around the conductor A at a distance of 5 cm from the conductor to the magnetic field produced around the conductor B at a distance of 2 cm from this conductor is

Solution:
QUESTION: 20

Same amount of current flows in the same direction .long the two parallel conductors separated by a small distance:

Solution:

When a conductor carries current it emits magnetic field around it . By the right-hand rule, a current out of the page in a field up gives a force to the left. Two parallel wires carrying currents in the same direction attract one another; wires with currents going in opposite directions repel.

QUESTION: 21

When an electric current flows through a long solenoid, magnetic field is set up in and around the solenoid :

Solution:
QUESTION: 22

Magnetic field produced at the centre of a current carrying circular wire is :

Solution:
QUESTION: 23

In all the electrical appliances, the switches are put in the

Solution:

Switches must be fitted onto the live wire so that opening it will disconnect (isolate) the appliance from the high voltage live wire. (If the switch is placed in the neutral wire, the electrical appliance is still connected to the high voltage live wire even when the switch is opened.)

QUESTION: 24

Which of the following properties of a proton can change while it moves freely in a magnetic field ?

Solution:

The magnetic force exerted will be perpendicular to the direction of motion of the proton. As we know when when force acting is perpendicular to the direction of moving charge, work done will be zero. It means kinetic energy does not change. The force is able to change the direction (velocity) of the proton but not its speed (magnitude). Thus momentum and velocity changes.

QUESTION: 25

A positively charged particle say an alpha particle projected towards west is deflected towards north by a magnetic field. The direction of the magnetic field is :

Solution: