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:
\(v_e = \frac{\sqrt{2GM}}{R}\)
Which of these is a derived unit?
Kilogram
Metre
Newton
Second
Correct answer is C
Examples of Fundamental Quantities ; Mass, kilogram, kg ; Electric Current, ampere, A ; Temperature, kelvin, K ; Amount of Substance, mole, Mol.
In which of the following situations is friction not useful?
Operation of a grinding machine
Walking
Application of brakes
Moving piston in a sleeve
Correct answer is D
friction, force that resists the sliding or rolling of one solid object over another.
Examples of friction in our daily life