physics

A 90cm uniform lever has a load of 30N suspended at 15cm from one of its ends. If the fulcrum is at the center of gravity; the force that must be applied at its other end to keep it in horizontal equilibrium is?

A. 15N B. 20N C. 30N D. 60N Correct Answer: Option B - 20N Explanation Since the lever is a…

4 years ago

A piece of stone attached to one end of a string is whirled round in a horizontal circle and the string suddenly cuts. The stone will fly off in a direction?

A. perpendicular to the circular path B. parallel to the circular path C. tangential to the circular path D. towards…

4 years ago

The stylus of a phonograph record exerts a force of 7.7 x 10−²N on a groove of radius 10^-5m. Compute the pressure exerted by the stylus on the groove

A. 2.45 x 108 Nm-2 B. 3.45 x 108 Nm-2 C. 4.90 x 108 Nm-2 D. 2.42 x 108 Nm-2 Correct Answer: Option A…

4 years ago

Water does not drop through an open umbrella of silk materials unless the inside of the umbrella is touched. This is due to?

A. capilarity B. osmotic pressure C. viscosity D. surface tension Correct Answer: Option D - surface tension Explanation Surface tension…

4 years ago

If a force of 50N stretches a wire from 20m to 20.01m; what is the amount of force required to stretch the same material from 20m to 20.05m?

A. 250N B. 200N C. 100N D. 50N Correct Answer: Option A - 250N Explanation Original length = 20m first…

4 years ago

A cell whose internal resistance is 0.5Ω delivers a current of 4A to an external resistor. The loss voltage of the cell is?

A. 1.250V B. 2.000V C. 8.000V D. 0.125V Correct Answer: Option B = 2.000V Explanation E = V + v…

4 years ago

A man exerts a pressure of 2.8 x 10³Nm‾² on the ground and has 4 x 10−²m² of his feet in contact with the ground. The weight of the man is?

A. 102N B. 70N C. 140N D. 112N Correct Answer: Option D - 112N Explanation Pressure = Force / Area…

4 years ago

Transverse waves can be distinguished from longitudinal waves using the characteristic of?

A. diffraction B. refraction C. polarization D. reflection Correct Answer: Option C = polarization

4 years ago

Metal rods of length 20m each are laid end to end to form a bridge at 25°C. What gap will be provided between consecutive rails for the bridge to withstand 75°C? [Linear expansivity of the material = 2.0 x 10^-5K‾¹]

A. 0.20m B. 0.22m C. 0.25m D. 0.02m Correct Answer: Option D = 0.02m Explanation Safety gap = expansion of…

4 years ago

A 50W electric heater is used to heat a metal block of mass 5kg. If in 10 minutes a temperature rise of 12°C is achieved; the specific heat capacity of the metal is?

A. 400 J kg-1K-1 B. 500 J kg-1K-1 C. 390 J kg-1K-1 D. 130 J kg-1K-1 Correct Answer: Option B…

4 years ago
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