Mix Test - 6...

The force per unit length is 10^-3 N on the two current-carrying wires of equal length that are separated by a distance of 2 m and placed parallel to each other. If the current in both the wires is doubled and the distance between the wires is halved, then the force per unit length on the wire will be:

Two alpha particles are moving perpendicular to the magnetic field. The radius of the circular path is \(r_{1}\) for the the particle moving with speed \(v_{1}\) and \(r_{2}\) for the particle moving with speed \(v _{2}\). If \(v _{1}\) is greater than \(v _{2}\), then:

The minimum value of magnetising intensity that is required to bring the magnetized material to its original state is called:

In a moving coil galvanometer, if the current flowing through it is increased, then the deflection in the coil will:

An electron is moving in a circular orbit in a magnetic field of \(2 \times 10^{-4}\) weber/m\(^{2}\). Its time period of revolution is:

Consider an infinitely long cylindrical straight conductor of radius \(r =2\) mm carrying current \(i=5\) A having uniform current density. At what distance \(d\) from the center of the wire is the value of the magnetic field \(1\) mT? (use \(\mu_{0}=4 \pi \times 10^{-7}\) H/m and assume r \(>\) d)

The current in the toroid of average radius r and number of turns N is I, then magnetic field intensity B inside the toroid is related to the average radius r as:

If two different particles of same initial velocity and charge fall perpendicularly into a uniform magnetic field and follows a circular path, then:

Current sensitivity of a moving coil galvanometer is 5 div/mA and its voltage sensitivity (angular deflection per unit voltage applied) is 20 div/V. The resistance of the galvanometer is:

Which of the following statements are true regarding Biot – Savart’s law?

(i) According to Biot – Savart’s law magnetic field is directly proportional to the length of the element.

(ii) Biot – Savart’s law deals with electric field.

(iii) Magnetic field is directly proportional to current through the conductor.

What happens to the strength of electromagnet if the soft iron core is put into it?

A circular coil A of radius ‘a’ carries current ‘I’. Another circular coil B of radius ‘2a’ also carries the same current of ‘I’. The magnetic fields at the centers of the circular coils are in the ratio of:

The current in the rectangular loop of area \(A\) is I. If this loop is placed in the uniform magnetic field of intensity \(B\) and the angle between the magnetic field and the area is \(\theta\), then the torque on the loop will be:

The magnetic field intensity at a distance from  a long wire carrying current i is 0.4 tesla. The  magnetic field intensity at a distance 2r is:

The relation between flowing current \((i)\) and deflection \((\theta)\) obtained in moving coil galvanometer will be:

A rectangular coil of length \(40\) cm and width \(10\) cm consists of \(10\) turns and carries a current of \(16\) A. The coil is suspended such that the normal to the plane of the coil makes an angle of \(60^{\circ}\) with the direction of a uniform magnetic field of magnitude \(0.60\) T. Find the magnitude of the torque experienced by the coil.

A current carrying rectangular loop is placed in the uniform magnetic field, if the angle between the area vector and the magnetic field is increased then the torque on the loop will:

The magnetic field intensity inside the toroid is B. If the current in the toroid is doubled then the magnetic field intensity inside the toroid will become:

The magnetic field \(\overrightarrow{dB}\) at a point \(\vec{r}\) distance away from a current element \(\overrightarrow{dl}\) carrying a current \(I\) is given by:

If the direction of flow of current is opposite in the two parallel wires separated by a small distance, then the wires will:

A charged particle of charge q and mass m is moving in a magnetic field B with a velocity v. If the velocity is perpendicular to the magnetic field then the acceleration of the charged particle will be:

Permanent magnet can be made by:

A moving coil galvanometer can be converted into a ammeter by connecting to the moving coil galvanometer:

Electromagnets are used in:

A square coil of side 20 cm consists of 30 turns and carries a current of 10 A, then the magnetic moment of the coil is:

The current carrying rectangular loop is placed in the uniform magnetic field, the torque on the loop will be maximum when the angle between the area vector and the magnetic field is:

What should be the properties of the core of electromagnets?

The current sensitivity of a moving coil galvanometer increases by 20% when its resistance increases by a factor 2 while keeping the number of turns constant. The voltage sensitivity changes by _________increases/decreases.

The earth's magnetic induction at a certain point is \(7 \pi \times 10^{-5}\) Wb/m\(^{2}\). This is to be annulled by the magnetic induction at the center of a circular conducting loop of radius \(5 cm\). The required current in the loop is: \((\mu_{0}=4 \pi \times 10^{-7}\) TA\(^{-1}\) m\()\)

Consider the following loop for Ampere's law. In the equation \(\oint B . dl = \mu _{0} i\), 'i' denotes the sum of the following currents: