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.
I < III < II
II < I < III
II < III < I
I < II
Correct answer is C
Alpha particles are highly ionising because of their double positive charge, large mass (compared to a beta particle) and because they are relatively slow.
They can cause multiple ionisations within a very small distance.
And the gamma radiation has the least ionising power.
In doping an intrinsic semiconductor to produce a p-type semiconductor,
the semiconductor is heated up
a donor element is added
an acceptor element is added
the semiconductor is conducted to a battery
Correct answer is C
If the dominant impurity atoms are ACCEPTOR type in the semiconductor, it will have a majority of holes over the electrons [p-type]
One major reason why electrical appliances in homes are normally earthed is that the-----------
person touching the appliance is safe from electric shock
appliances are maintained at a higher p.d. than the earth
appliances are maintained at a lower p.d. than the earth
appliances are maintained at the same p.d. with that of the earth
Correct answer is A
Earthing of an electrical appliance meant the outer metallic case of appliance is connected with earth, wire which is welded to the end of a copper rod and it is burned in the ground. It save the appliance during short-circuiting by passing Excessive current to earth
A lamp is rated 240 V, 60 W. Determine the resistance of the lamp when lit?
120\(\Omega\)
240\(\Omega\)
540\(\Omega\)
960\(\Omega\)
Correct answer is D
P = 60w, V = 240v, R = ?
P = \(\frac{V^2}{R}\)
: 60 = \(\frac{240^2}{R}\)
→ R * 60 = 57,600
R = \(\frac{57,600}{60}\)
R = 960\(\Omega\)
In a series R-L-C circuit at resonance, impedance is----
maximum
minimum
capacitive
inductive
Correct answer is A
Since the current flowing through a parallel resonance circuit is the product of voltage divided by impedance, at resonance the impedance, Z is at its maximum value.
(Z=R )