Explanation

The frequency heard by the observer as the car approaches is given by the Doppler effect formula:

f' = f * (v / (v - v_s))

where f = 500 Hz, v = 340 m/s, and v_s = 20 m/s.

f' = 500 * (340 / (340 - 20))

= 500 * (340 / 320)

= 500 * 1.0625

= 531.25 Hz

Explanation

Explanation

The Nearctic region includes North America, where animals like prairie dogs, buzzards, opossums, and mountain lions/dogs are commonly found.

It is one of the major biogeographic realms.

Explanation

The ABO blood group gene is located on chromosome number 9.

It codes for glycosyltransferase enzymes that determine blood type.

Explanation

A terrestrial food chain typically starts with a producer (like grass), followed by primary consumers (herbivores like grasshoppers), then secondary consumers (like snakes), and ends with top predators (like eagles).

This sequence shows the correct flow of energy from plants to top carnivores.

Explanation

In SHM, total energy (kinetic + potential) remains constant if no external force or damping is present.

Though kinetic and potential energy change with time, their sum stays the same throughout the motion.

Explanation

The galactic bulge is the bright, dense center of a spiral galaxy.

It contains old stars.

It often a supermassive black hole at the core.

Explanation

e/m = 2E/B²r²

The formula is derived by equating the magnetic Lorentz force to the centripetal force and using the kinetic energy gained from the accelerating voltage E.

This formula correctly relates the charge-to-mass ratio of an electron to the magnetic field B, radius of the circular path r, and accelerating voltage E.

Explanation

When a body moves with uniform velocity, its speed and direction remain constant throughout the motion.

In such a case, the average velocity over any time interval is equal to the instantaneous velocity at any moment.

Explanation

An electric generator converts mechanical energy (like rotation from a turbine) into electrical energy using electromagnetic induction.

The mechanical movement causes a conductor to cut magnetic field lines, generating electric current.