Two conducting wires A and B are made ofsame material. If the length of B is twice that of A and the radius of circular cross-section of A is twice that of B, then their resistances R_A and R_B arein the ratio

• 2 : 1

• 1 : 2

• 1 : 8

• 1 : 4

Consider the following statements:

A real image

1. can be formed on a screen
2. is always magnified and inverted

Which of the statements given above is/are correct?

• 1 only

• 2 only

• Both 1 and 2

• Neither 1 nor 2

Van de Graaff generator is used for

• accelerating charged particles

• generating large currents

• generating electric field

• generating high-frequency voltage

Bernoulli's principle is based on which one among the following laws?

• Conservation of mass

• Conservation of momentum

• Conservation of angular momentum

• Conservation of energy

The displacement (x)-time (t) graph given above approximately represents the motion of a

• simple pendulum placed in vacuum

• simple pendulum immersed in water

• simple pendulum placed in outer space

• point mass moving in air

The current (I)-voltage (V) plot of a certain electronic device is given above. The device is

• a semiconductor

• a conductor which obeys Ohm's law

• a superconductor

• an insulator

If speed of light in air is 3 x 10⁸ m/s, the speed oflight in glass (with refractive index 1.5) would be

• 2 x 10⁸ m/s

• 4.5 x 10⁸ m/s

• 3 x 10⁸ m/s

• 1.5 x 10⁸ m/s

While looking at an image formed by a convex lens (one half of the lens is covered with a black paper), which one of the following will happen to the image?

• Half of the image will be visible

• Intensity of the image will be diminished

• Image will be inverted now

• One can see an image of smaller size

A sound wave has frequency of 2 kHz and wavelength of 35 cm. Ifan observer is 1.4 km away from the source, after what time interval could the observer hearthe sound?

• 2 s

• 20 s

• 0.5 s

• 4 s

A fuse is used in an electric circuit to

• break the circuit when excessive current flows through the circuit

• break the circuit when power gets off

• indicate if the current is flowing uninterrupted

• complete the circuit for flow of current