TEST SERIES - 65 (II)

Magnetite is a/an

• Natural magnet

• Electromagnet

• U-shaped magnet

• None of the above

The heating element of an electric heater should be made of a material having

• High specific resistance and high melting point

• High specific resistance and low melting point

• Low specific resistance and low melting point

• Low specific resistance and high melting point

The work done in moving a positive charge on an equipotential surface is

• Finite and positive

• Infinite

• Finite and negative

• Zero

Increasing the charge on the plates of a capacitor means

• Increasing the capacitance

• Increasing the potential difference between the plates

• Both (a) and (b)

• None of the above

The resistance of an ideal voltmeter is

• Zero

• Very low

• Very high

• Infinite

The resistance of an ideal ammeter is

• Zero

• Very low

• Very high

• Infinite

Consider the electromagnetic radiations having wavelengths 200 nm, 500 nm and 1000 nm. Which wavelength(s) of the following can make visual sensation to a human eye?

• Only 500 nm

• 200 nm and 500 nm

• 200 nm and 1000 nm

• 500 nm and 1000 nm

The split ring in motion is called

• Armature

• Rotor

• Commutator

• Core

In a hydel station the motion produced in turbines is due to the

• Burning of coal

• Burning of diesel

• Flow of water

• Production of steam

Vibration magnetometer works on the principle of

• Torque acting on the bar magnet

• Force acting on the bar magnet

• Both the force and the torque acting on the bar magnet

• None of the above