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# Test : Magnetic Effects of Current- 4

## 25 Questions MCQ Test Science Class 10 | 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

### When the main switch of the house circuit is put off, it disconnects the :

Solution:

The correct option is D.
In this case when the main switch of the house is switched off it would disconnect the live wire and the neutral wire.

QUESTION: 3

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

Solution:

Every fuse has given particular thickness to with stand particular electric current strength, the current value 8A means that the fuse will melt or will burn out if the current passing through the fuse exceeds 8A , other than that the fuse will work fine even if the current supplied lower than that of 8A .

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 magnetic field produced by a current carrying solenoid is similar to the magnetic field produced by a bar magnet. The magnetic field lines inside the solenoid are in the form of parallel straight lines and along the axis of 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:

Among given options half revolution is the right answer.

The current induced by the magnetic field in the rectangular coil made up of copper wire is being turned in order to rotate in the magnetic field, at every turn, the direction of induced current changes and being a vector quantity, induced current changes every half revolution.

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:

Magnetic field produced is directly proportional to the current flowing and inversely proportional to the distance from the conductor. Since current flowing in both conductors is same only distance matters here. Since field is inversely proportional to distance ;
B(A) / B(B)  = d(B) / d ( A) = 0.2/0.5
=>  0.4

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:

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.)
This may cause the user to get an electric shock if he touches the live wire.
That’s why the switches are put in the live wire.

QUESTION: 24

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

Solution:

Each moving charged particle in a magnetic field experiences a force. The direction of force experienced by a positive charge is given by Fleming's left hand rule. The force acting on the proton would change both velocity and momentum.

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:

The correct answer is A as Here the direction of current toward west and towards north .So by Fleming left hand rule the direction of magnetic field is upward. the rule used in Fleming left hand rule which states that if we stretch our thumb forefinger and middle figure of our left hand perpendicular to each other in such a way that forefinger points the direction of magnetic field and middle figure points the direction of current and middle figure points the direction of current then thumb will represent the direction of force.