physics

Metal cables are used as telephone wires because?

A. they are cheap B. they are sourced locally C. the speed of sound in them is very low D.…

4 years ago

A man standing 2 m from a charcoal fire is warmed mainly by?

A. convection B. radiation C. refraction D. conduction Correct Answer: Option B - radiation Explanation Radiation is the method of…

4 years ago

It is observed that water will wet a clean glass because the?

A. cohesion of water to glass is stronger than the cohesion of water molecules B. adhesion of water molecules is…

4 years ago

A heating coil rated 1000W is used to boil off completely 2kg of boiling water. the time required to boil the water is? [Special latent heat of Vaporization of water = 2.3 x 106 Jkg‾¹]

A. 1.15 x 104s B. 1.15 x 103s C. 4.6 x 104s D. 4.6 x 103s Correct Answer: Option D…

4 years ago

If the pressure of the vapour on top of an enclosed liquid is equal to the atmospheric pressure. What will be the temperature of the liquid enclosed?

A. room temperature B. boiling point C. freezing point D. standard temperature Correct Answer: Option B - boiling point Explanation…

4 years ago

An electric heater rated 220V; 1000W is immersed into a bucket full of water; calculate the mass of water if the temperature changes from 30°C to 100°C and the current flows for 300seconds. [specific heat capacity of water = 4200 jkg‾¹K‾¹]

A. 4.28 kg B. 42.86 kg C. 1.02 kg D. 7.14 kg Correct Answer: Option C = 1.02 kg Explanation…

4 years ago

At 4°c; the volume of a fixed mass of water is?

A. constant B. minimum C. maximum D. zero Correct Answer: Option B - minimum Explanation Anomalous expansion of water is…

4 years ago

The thermometer whose reading is indicated by a change in colour of its thermometric property is the?

A. bi-metallic strip thermometer B. thermocouple C. platinum resistance thermometer D. optical pyrometer Correct Answer: Option D - optical pyrometer…

4 years ago

A plastic sphere floats in water with 50% of its volume submerged. if it floats in glycerine with 40% of its volume submerged; the density of the glycerine is?

A. 1400 kgm‾³ B. 1250 kgm‾³ C. 500 kgm‾³ D. 1000 kgm‾³ Correct Answer: Option B - 1250 kgm‾³ Explanation…

4 years ago

If a load of mass 10N stretched a cord by 1.2cm. What is the total work done?

A. 6.0 x 10‾²J B. 7.6 x 10‾²J C. 1.8 x 10‾²J D. 6.6 x 10‾²J Correct Answer: Option A…

4 years ago
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