Mix Test - 9...

Which among the following, is not a cause for power loss in a transformer-

A battery is connected to the conductor of non-uniform cross section area. The quantities or quantity which remains constant is-

The current sensitivity of a galvanometer increases by 20%. If its resistance also increases by 25%, the voltage sensitivity will.

In a hydrogen atom the electron moves in an orbit of radius 0.5 Å making 10 revolutions per second, the magnetic moment associated with the orbital motion of the electron will be

An air-cored solenoid with length 30 cm, area of cross-section 25 \(cm^2\) and number of turns 800, carries a current of 2.5 A. The current is suddenly switched off in a brief time of \(10^{-3}\) s. Ignoring the variation in magnetic field near the ends of the solenoid, the average back emf induced across the ends of the open switch in the circuit would be

A sinusoidal voltage of peak value 283 V and frequency 50 Hz is applied to a series LCR circuit in which R = 3 \(\Omega\), L = 25.48 mH, and C = 796 \(\mu\)F, then the power dissipated at the resonant condition will be-

If both the number of turns and core length of an inductor is doubled keeping other factors constant, then its self-inductance will be-

Assertion (A): To increase the range of an ammeter, we must connect a suitable high resistance in series to it.

Reason (R): The ammeter with increased range should have high resistance.

Assertion (A): An electron has a high potential energy when it is at a location associated with a more negative value of potential, and a low potential energy when at a location associated with a more positive potential.

Reason (R):Electrons move from a region of higher potential to region of lower potential.

Assertion(A): A magnetic needle free to rotate in a vertical plane, orients itself (with its axis) vertical at the poles of the earth.

Reason (R): At the poles of the earth the horizontal component of earth’s magnetic field will be zero.

Assertion(A): A proton and an electron, with same momenta, enter in a magnetic field in a direction at right angles to the lines of the force. The radius of the paths followed by them will be same.

Reason(R): Electron has less mass than the proton.

Assertion (A): On Increasing the current sensitivity of a galvanometer by increasing the number of turns, may not necessarily increase its voltage sensitivity.

Reason(R ): The resistance of the coil of the galvanometer increases on increasing the number of turns.

Which of the following statement is true?

If the secondary coil has a greater number of turns than the primary,

We need to step-up the voltage for power transmission, so that

A power transmission line feeds input power at 2300 V to a step down transformer with its primary windings having 4000 turns. The number of turns in the secondary in order to get output power at 230 V are