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NECO Physics Past Questions & Answers - Page 57

281.

A waterfall is 630cm high. What is the change in temperature of a quantity of water that falls from the top to the bottom of the waterfall? (Neglect heat losses to the surroundings, take g as 10 ms-2 and specific heat capacity of weather as 4200J kg-1K-1

A.

0.15°C

B.

1.50°C

C.

15.00°C

D.

21.00 °C

E.

50.00°C

Correct answer is B

water height as 630cm, gravity = 10m/s2,   specific heat capacity of weather as 4200J 

Temperature change = ghc630104200

= 1.5C

282.

What is X in the equation given below? 42He + 94Be → 126C + X

A.

electron

B.

hydrogen

C.

lithium

D.

neutron

E.

proton

Correct answer is D

No explanation has been provided for this answer.

283.

Notes of the same frequency sounded on a piano and on a flute may differ in

I. pitch
II. quality
III. Loudness

A.

I only

B.

II only

C.

I and III only

D.

II and III only

E.

I, II and III

Correct answer is B

Quality is that characteristic note which distinguishes the two sounds of the same loudness and same pitch but emitted by two different instruments.

284.

What is the energy stored in a 10μ F capacitor if the potential difference between the plates is 40 V?

A.

2.0 × 10-4J

B.

8.0 ×10-4J

C.

4.0 × 10-3J

D.

8.0 × 10-3J

E.

1.6 × 10-2J

Correct answer is D

No explanation has been provided for this answer.

285.

Which scientist discovered natural radioactivity?

A.

Enrico Fermi

B.

Henri Becquerel

C.

Marie Curie

D.

Micheal Faraday

E.

Niels Bohr

Correct answer is B

No explanation has been provided for this answer.