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.
283.5N
975.0N
216.5N
716.5N
Correct answer is D
The forces opposing the motion of the device are "mgsin θ" and "μN" where N is the normal reaction
From the diagram, on resolving to components, N = mgcos θ
Total opposing force = mgsin θ + μmgcos θ = mg(sin θ + μcos θ)
= 100 × 10 × (sin 30° + 0.25 × cos 30°)
= 1000 × (0.5 + 0.2165)
= 1000 × 0.7165
= 716.5 N
The most appropriate value of fuse for a kettle rated 220 V, 1.06 kW is
3A
6A
5A
4A
Correct answer is C
V = 220V, P = 1.60KW = 1060W, I = ?
P = IV
I = \(\frac{P}{V} = \frac{1060}{220}\)
≈ 5A.
\(\frac{\sqrt{GR}}{2}\)
\(\frac{\sqrt{2GM}}{R}\)
\(\frac{\sqrt{2G}}{R}\)
\(\frac{\sqrt{GM}}{R}\)
Correct answer is B
The expression for the escape velocity \(v_e\) of an object from a planet of mass M and radius R using the universal gravitational constant G is:
\(v_e = \frac{\sqrt{2GM}}{R}\)
Increasing the frequency of a sound wave produces a sound with
higher pitch
longer wavelength
more overtones
reduced loudness
Correct answer is A
The pitch of a sound is determined by its frequency. Higher frequencies correspond to higher pitches. For example, a high-pitched sound like a whistle has a higher frequency than a low-pitched sound like a drum.
\(\frac{qBr}{m}\)
\(\frac{mr}{qB}\)
\(\frac{qm}{Br}\)
\(\frac{mq}{r}\)
Correct answer is A
F = qvB ( force on moving charge in a magnetic field) F = \(\frac{mv^2}{r}\)
equating F
qvB = \(\frac{mv^2}{r}\)
qB = \(\frac{mv}{r}\)
qBr = mv
Therefore, v = \(\frac{qBr}{m}\)