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.
2.0 * 106 NC -1
2. 5 * 106 NC -1
1.0 * 107 NC -1
4.0 * 107 NC -1
Correct answer is B
v = E*d, => E = v/d
i.e E 107/4 = 2.5 * 106 NC-1
3 Ω
2 Ω
1 Ω
6 Ω
Correct answer is A
1 = V/R = E/R+r , if r = 2Ω
V = 3/5 E
=> 3E/5R = E/R+2
i.e 3E(R+2) = 5RE
3RE + 6E = 5RE
i.e 3R + 6 = 5R
6 = 5R - 3R
=> 2r = 6 i.e R = 6/2 = 3Ω
4.5Ω
1.0Ω
8.0Ω
2.0Ω
Correct answer is D
Efficiency = power out put/power input * 100/1
= power out put/ power + that due * 100/1
to internal resistance
=> 75/1 = 12R *100/1
12(R+r)
i.e 75/100 = 6/6+r => 75 (6+r) = 100/*6
i.e 450 + 75r = 600
75r =600 - 450
i.e r = 150/75 = 2Ω
i.e r = 2Ω
2.0 J
4.0 J
12.0 J
2.4 J
Correct answer is A
P = F/A => F = PA = PV/L
Volume V\(_2\) = 6 * 2 x 10\(^{-6}\)
W = PΔV = 2 x 10\(^5\) * (12 x 10\(^{-6}\) - 2 x 10\(^{-6}\))
= 2 x 10\(^5\) 10 x 10\(^{-6}\)
= 2.0J
A string is fastened tightly between two walls 24cm apart. The wavelength of the second overtone is
24cm
16cm
12cm
8cm
Correct answer is B
For a string fixed at both ends and plucked at the middle, the fundamental frequency is given
by f0 = v/λ, where v = velocity of sound, λ = wave length.
At its fundamental, note, the the length of the string is given l = λ/2, => λ0 = 2l, where λ0 = wave length fundamental note. for the first over tone, λ1 = l.
For the second over tone, λ2 = 21/3 = (2 x 24)/3 = 16cm.
i.e. λ2 = 16cm.