A current carrying wire kept in a uniform magnetic field will experience a maximum force, when it is

A current I flows through a long straight conductor which is bent into a circular loop of radius R in the middle as shown in the figure.

The magnitude of the net magnetic field at point O will be

The oscillating magnetic field in a plane electromagnetic wave is given as \(B_{y}=\left(8 \times 10^{-6}\right) \sin \left[2 \times 10^{11} t+300 \pi x\right] \mathrm{T}\) wavelength of the cm wave is

10 cm is a wavelength corresponding to the spectrum of

Three long, straight parallel wires, carrying current are arranged as shown in the figure. The force experienced by a 25 cm length of wire C is

A conducting circular loop of radius r carries a constant current i. It is placed in a uniform magnetic field B, such that B is perpendicular to the plane of the loop. The magnetic force acting on the loop is

Beams of electrons and protons move parallel to each other in the same direction,they

What is the net force on the rectangular coil?

A rectangular loop carrying a current i is situated near a long straight wire such that the wire is parallel to the one of the sides of the loop and is in the plane of the loop. If a steady current I is established in wire as shown in figure, the loop will

The coil of a galvanometer consists of 100 turns and effective area of 1 cm². The restoring couple is 10^-8 Nm rad ^-1. The magnetic, fieldbetween poles is of 5 T. Current sensitivity of this galvanometer is

The wire which connects the battery of a car to its starter motor carries current of 300 A during starting. Force per unit length between wires (wires are 0.7 m long and 0.015 m distant apart) is

In an ammeter 0.5% of main current passes through galvanometer. If resistance of galvanometer is G, the resistance of ammeter will be

A proton and an alpha particle both enter a region of uniform magnetic field B, moving at right angles to the field B. If the radius of circular orbits for both the particles is equal and the kinetic energy acquired by proton is 1 MeV, the energy acquired by the alpha particles will be :

Two similar coils of radius R, are lying concentrically with their planes at right angles to each other. The currents flowing in them are I and 2 I respectively. The resultant magnetic field at the centre will be :

Total e.m. power that is incident on a roof of dimension \((8m\times 10m)\) on the surface of earth is

If \({ \mu }_{ 0 },{ \mu }_{ r },{ \epsilon }_{ 0 }and{ { \epsilon }_{ r } }\) as the absolute permeability relative permeability, absolute permittivity and relative permittivity of the medium, then the velocity of electromagnetic wave in a medium is

Displacement current goes through the gap between the plates of a capacitor when the charge of the capacitor

Which of the following statements about electromagnetic waves is/are correct
(1) X-rays in vacuum travel faster than light waves in vacuum
(2) The energy of x-rays photon is greater than that of a light photon
(3) light can be polarised by x-rays cannot

During the propagation of electromagnetic waves in a medium

The amplitude of an electromagnetic wave A is a and of another B is 3 a. Their frequencies are the same for the Maximum waves. Then

Which of the following is not true for electromagnetic waves ?

The velocity of light in vacuum can be changed by changing

An EM wave of intensity I falls on a surface kept in vacuum and experts radiation pressure kept in vacuum and experts radiation pressure p on it. Which of the following are true?

The electric field intensity produced by the radiations coming from 100 W bulb at a 3m distance is E. The electric field intensity produced by the radiations coming from 50w bulb at the same distance is:  

Assertion : Gamma rays are electromagnetic waves having the smallest wavelength.
Reason : Gamma rays are having the lowest frequency.
Codes:
A) Both A and R are true and R is the correct explanation of A
B) Both A and R are true but R is NOT the correct explanation of A
C) A is true but R is false
D) A is false and R is true

Assertion : Microwaves are considered suitable for radar system.
Reason : Microwaves are of shorter wavelength.
Codes:
A) Both A and R are true and R is the correct explanation of A
B) Both A and R are true but R is NOT the correct explanation of A
C) A is true but R is false
D) A is false and R is true

Assertion : X-ray travels with the speed of light.
Reason : X-ray is an e.m. wave.
Codes:
A) Both A and R are true and R is the correct explanation of A
B) Both A and R are true but R is NOT the correct explanation of A
C) A is true but R is false
D) A is false and R is true

Assertion: If an electron is not deflected when moving through a certain region of space, then the only possibility is that no magnetic field is present in that region.
Reason: Force on electron is directly proportional to the strength of the magnetic field.
Codes:
A) Both A and R are true and R is the correct explanation of A
B) Both A and R are true but R is NOT the correct explanation of A
C) A is true but R is false
D) A is false and R is true

Assertion : Cyclotron is a device which is used to accelerate the positive ion.
Reason : Cyclotron frequency depends upon the velocity.
Codes:
(a) If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
(b) If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
(c) If the Assertion is correct but Reason is incorrect.
(d) If both the Assertion and Reason are incorrect.

Assertion (A) : The magnetic field intensity at the centre of a circular coil carrying current changes, if the current through the coil is doubled.
Reason (R) : The magnetic field intensity is dependent on current in conductor.
Codes:
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true but R is NOT the correct explanation of A
(c) A is true but R is false
(d) A is false and R is also false