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.
Thermionic emission is the process whereby?
β - rays are produced
holes are produced
x - rays are produced
electrons leave a hot element
Correct answer is D
Thermionic emission is ejection of electron from a metal surface as a result of heating.
3.47 x 1018
6.93 x 10 20
3.47 x 1020
6.93 x 1018
Correct answer is A
The number of disintegration,∆N in time interval At, is given by
- ∆N = N∆t
Where N is the number of atoms present at the time t
But ^ = (0.693)/T
= 0.693 ÷ 20
= 0.0347
∴ ∆N = 0.0347 \(\times\) 10\(^20\)
= 3.47 \(\times\) 10\(^18\)
Cancerous cells can be destroyed by?
ultraviolet rays
alpha particules
x - rays
infrared rays
Correct answer is C
Cancerous cells can be destroyed with a high penetrating radiation which is x - rays
5.60 v
24.00 v
0.24 v
2.40 v
Correct answer is D
Number of tunes, n = 500
Area, A = 0.2m + 0.2m = 0.4m2
change of flux density A B
= 1.0 - 0.4 = 0.6T
Tune, t = 5 su
Induced emf, ξ = (AB AN)/AT
(0.6 x 0. 04 x 500)/5
= 2.4v
3.86 x 105J
3.56 x 105J
1.80 x 104J
2.16 x 105J
Correct answer is D
Energy generated = power X time = 60w x 1h = 60 x 60 x 60 ws = 216000j = 2.16 x 105J