JAMB Physics Past Questions & Answers - Page 303

1,511.

Which of the following quantities has the same unit as the watt?

A.

Force x time

B.

Force x distance

C.

Force x acceleration

D.

Force x velocity

Correct answer is D

No explanation has been provided for this answer.

1,512.

If light with photon energy 2eV is incident suitably on the surface of a metal with work function 3eV, then

A.

no electron will be emitted

B.

the few electrons emitted will have a maximum kinetic energy of 1eV

C.

the few electrons emitted will have a maximum kinetic energy of 3eV

D.

many electrons will be emitted

Correct answer is A

An electron can only be emitted if photon energy is equal or greater than work function of the plate

1,513.

A certain radioisotope of \(^{235}_{92}U\) emits four alpha particles and three beta particles. The mass number and the atomic number of the resulting elements respectively are

A.

219 and 87

B.

84 and 223

C.

223 and 87

D.

219 and 81

Correct answer is A

\(^{235}_{92}U\) \(\to\) 4\((^{4}_{2}\alpha)\) + 3\((^{0}_{-1}e)\) + \(^{b}_{a}y\)

a + (4 + 2) + (3x - 1) = 92 \(\Rightarrow\) a = 87

b + (4 x 4) + (3 x 0) = 235 \(\Rightarrow\) b = 219

\(^{b}_{a}Y\) = \(^{219}_{87}Y\)

1,514.

If two parallel conductors carry currents flowing in the same direction, the conducts will

A.

attract each other

B.

repel each other

C.

both move in the same direction

D.

have no effect on each other

Correct answer is A

No explanation has been provided for this answer.