A charged particle (charge q ) is moving n a circle of radius R with uniform speed v. The associated magnetic moment μ is given by:

• qvR/2

• qVR²

• qVR²/2

• qVR²/2

A steady current of 1.5 A flows through a copper voltameter for 10 min. If the electrochemical equivalent of copper is 30 x 10^-5 g C^-1, the mass of copper  deposited on the electrode will be:

• 0.40 g

• 0.50 g

• 0.67 g

• 0.67 g

A hollow cylinder has to charge q coloumb within it. Φ is the electric flux in a unit of voltmeter associated with the curved surface B, the flux linked with the plane surface A in a unit of voltmeter will be:

In mass spectrometer used for measuring the masses of ions, the are initially accelerated by an electric potential V and then made to describe semicircular paths of radius R using a magnetic field B. If V and B are kept constant, the ratio  will be proportional to:

• 1/R

• 1/R²

• R²

• R²

Three resistances P, Q, R each of 2 Ω and an unknown resistance S form the four arms of a Wheatstone's bridge circuit. When a resistance of 6 Ω is connected in parallel  to S the bridge gets balanced. What is the value of S? 

• 2 Ω

• 3 Ω

• 6 Ω

• 6 Ω

The electric and magnetic field of an electromagnetic wave are:

• in phase and parallel to each other

• in opposite phase and perpendicular to each other

• in opposite phase and parallel to each other

• in opposite phase and parallel to each other

Charge +q and -q are placed at points A and B respectively which are distance 2L apart, C is the midpoint between A and B.The work done in moving a charge + Q along the semicircle CED is:

38.

A common emitter amplifier has a voltage gain of 50, an input impedance of 100 Ω and an output impedance of 200 Ω. The power gain of the amplifier is:

• 500

• 1000

• 1250

• 1250

In radioactive decay process, the negatively charged emitted beta particles are:

• the electrons present inside the nucleus

• the electrons produced as a result  of the decay of neutrons inside the nucleus

• the electrons produced as a result of collisions between atoms

• the electrons produced as a result of collisions between atoms

A small coin is resting on the bottom of a beaker filled with a liquid. A ray of light from the coin travels up to the surface of the liquid and moves along its surface (see figure).



How fast is the light travelling in the liquid?

• 1.8 x 10⁸ m/s

• 2.4 x 10⁸ m/s

• 3.0 x 10⁸ m/s

• 3.0 x 10⁸ m/s