Physics Questions and Answers
If you want to learn more about the nature and properties of matter and energy or you're simply preparing for a Physics exam, these Physics past questions and answers are ideal for you.
If you want to learn more about the nature and properties of matter and energy or you're simply preparing for a Physics exam, these Physics past questions and answers are ideal for you.
Which of the following features is NOT a characteristic of natural radioactivity?
Radioactivity is a nuclear phenomenon
Radioactivity is exhibited only by elements of mass number greater than 206
The radioactivity of an element is affected by electric and magnetic fields in the surroundings
Radioactive substances emits three types of radiations, a-rays, \(\beta\)-rays and y-rays
The radioactive element is transformed into a new element
Correct answer is B
Natural radioactivity is exhibited by elements of atomic numbers of 83 or more
Which of the following statements about electrolysis is NOT correct?
The substances in solution in the electrolyte become ionized
Ions are electrically charged and are attracted towards electrodes when a potential difference is applied
Ions may be discharged at the electrodes, forming bubbles or deposits
The mass deposited depends upon the length of time for which current flows
The mass of gas set free or metal deposited is proportional to the square of the current
Correct answer is E
No explanation has been provided for this answer.
6000V
600V
240V
60V
24V
Correct answer is B
For transformers, \(\frac{V_p}{V_s}\) = \(\frac{N_p}{N_s}\) = \(\frac{I_p}{I_s}\)
\(\frac{500}{2500}\) = \(\frac{120}{V_s}\)
Vs = 600v
i only
ii only
iii only
ii and iii only
i,ii and iii
Correct answer is B
No explanation has been provided for this answer.
14.4\(\Omega\)
28.8\(\Omega\)
144\(\Omega\)
288\(\Omega\)
2880\(\Omega\)
Correct answer is B
Heat energy = Electrical energy
6 x 105 = \(\frac{V^2}{R}\)t
R = \(\frac{240 \times 240 \times 5 \times 60}{6 \times 105}\)
= 28.8\(\Omega\)