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JAMB Physics Past Questions & Answers - Page 243

1,211.

Which of the following statements is TRUE of photoelectric effect?

A.

it cannot occur in liquids

B.

the energy of the emitted electrons is independent of the work function of the surface

C.

the energy of the emitted electron depends on the wavelength of the incident light

D.

the greater the intensity of the incuident light, the greater the incident of the emitted electron

Correct answer is C

The photoelectric effect is the emission of electrons when electromagnetic radiation, such as light, hits a material.

The frequency of the incident light on the substance determines the kinetic energy of the emitted electrons.

The number of electrons emitted and the intensity of light incident are proportional to each other.

1,212.

What type of reaction is represented by the following scheme? 21X + 21Y + 32Z + 10n + energy

A.

Fusion reaction

B.

Fission reaction

C.

Chain reaction

D.

Radioactive decay

Correct answer is A

No explanation has been provided for this answer.

1,213.

A galvanometer of resistance 20Ω is to be provided with a shunt that 110 of the whole current in a circuit passes through the galvanometer. The resistance of the shunt is

A.

2.00Ω

B.

2.22Ω

C.

18.00Ω

D.

18.22Ω

Correct answer is B

110I x 20 = 910I x Rs

Rs = 2.22Ω

1,214.

When two parallel wires carry currents in opposite directions, the force on either wire is

A.

away from the other wire

B.

zero, because the currents cancel each other

C.

twice as much as when the currents are in the same direction

D.

towards the other wire

Correct answer is A

No explanation has been provided for this answer.

1,215.

The direction of the magnetic field at a point in the vicinity of a bar magnet is

A.

always towards the north pole of the magnet

B.

always away from the south pole of the magnet

C.

along the line joining the point to the neutral point

D.

in the direction the north pole of a compass needle would point

Correct answer is D

No explanation has been provided for this answer.