CBSE Past Year MCQ Quiz

A charged particle of mass m having kinetic energy K passes undeflected through a region with electric field \(\vec{E}\) and magnetic field \(\vec{B}\) acting perpendicular to each other. The mass m of the particle will be :

A galvanometer of resistance G is converted into a voltmeter of range (0 − V) by connecting a resistor of 250 Ω with it. If resistor of 250 Ω is replaced by another resistor of 900 Ω, its range becomes (0 − 3 V). The resistance G of the galvanometer is :

A charged particle is moving in a uniform magnetic field \(\vec{B}\) with a constant speed v in a circular path of radius r. Which of the following graphs represents the variation of radius of the circle, with the magnitude of magnetic field \(\vec{B}\) ?

Four long straight thin wires are held vertically at the corners A, B, C and D of a square of side ‘a’, kept on a table and carry equal current ‘I’. The wire at A carries current in upward direction whereas the current in the remaining wires flows in downward direction. The net magnetic field at the centre of the square will have the magnitude :