# Magnetic Effects of Current and Magnetism (KVPY (Kishore Vaigyanik Protsahan Yojana) Stream SB-SX (Class 12 & 1st Year B.Sc.) Physics): Questions 7 - 9 of 11

Get 1 year subscription: Access detailed explanations (illustrated with images and videos) to 268 questions. Access all new questions we will add tracking exam-pattern and syllabus changes. View Sample Explanation or View Features.

Rs. 200.00 or

## Question number: 7

» Magnetic Effects of Current and Magnetism » Current Loop as Magnetic Dipole

MCQ▾

### Question

Two concentric circular coils of radius 14 cm and 40.0 cm having 45 and 20 number of turns carry currents 0.2 A and 0.48 A respectively and in opposite direction. The magnetic field produced at the common centre is –

### Choices

Choice (4) Response

a.

0.253 gauss perpendicular to the plane of the coil downward

b.

0.253 gauss perpendicular to the plane of the coil upward

c.

0.253 gauss perpendicular to the plane of the coil may be upward or downward

d.

0.253 gauss in the plane of the coil

## Question number: 8

» Magnetic Effects of Current and Magnetism » Para, Dia and Ferro-Magnetic Substances

Appeared in Year: 2015

MCQ▾

### Question

Consider the regular array of vertical identical current carrying wires (with direction of current flow as indicated in the figure below) producing through a horizontal table. If we scatter some diamagnetic particles on the table, they are likely to accumulate.

### Choices

Choice (4) Response

a.

Around regions such as B

b.

In circular regions around individual wires such as C

c.

Uniformly everywhere.

d.

Around regions such as A

## Question number: 9

» Magnetic Effects of Current and Magnetism » Biot - Savart Law

Appeared in Year: 2015

MCQ▾

### Question

A point charge Q rotates uniformly in a vertical circle of radius R = 1 mm. The axis of the circle is aligned along the magnetic axis of the earth. At what value of the angular speed 𝜔, the effective magnetic field at the centre of the circle will be reduced to zero? (Horizontal component of Earth’s magnetic field is 30 micro Tesla)

### Choices

Choice (4) Response

a.

b.

c.

d.

f Page