eCoaching | Online Home Tutors & Teachers
Question Options
A nuclide has the notation 48 / 23 X Which line in the table describes a different isotope of this nuclide? 23 50, proton number (atomic number) 24 nucleon number (mass number) 48, proton number (atomi
Forces of 30 N and 50 N act on the same body, but in different directions. Which value could not be the resultant force on the body? 10 N, 30 N, 50 N, 70 N
A body of mass 10 kg falling freely in the gravitational field close to the Moon’s surface has an acceleration of 1.6 m / s2. What is the gravitational field strength on the Moon? 0 N / kg , 1.6 N / kg, 10 N / kg , 16 N / kg
A 2 kg mass is moving at constant speed. The kinetic energy of the mass is 400 J. What is the speed of the mass? 0.4 m / s , 20 m / s , 200 m / s , 400 m / s
The efficiency of an electrical generator is 65 %. Which useful output can be expected if the energy input to the generator is 12 kJ? 4.2 kJ , 7.8 kJ , 19 kJ , 780 kJ
Which of the following correctly compares the forces between the molecules in steam, water and ice? ice steam water, ice water steam, steam water ice, water steam ice
Which instrument is most suitable for measuring a rapidly changing temperature? alcohol-in-glass thermometer, clinical thermometer, mercury-in-glass thermometer, thermocouple
Which does not normally use infra-red radiation? electric grill, intruder alarm, television remote controller, sunbed
A flash of lightning and the corresponding thunder clap are detected 6 s apart. It is calculated that the lightning struck about 1800 m away. On which assumption is the calculation based? Light reaches us almost instantaneously, but sound travels at 300 m / s., Light travels 300 m / s f
Which part of a video tape recording system does not rely on magnetic material for its operation? the drive motor, the power lead, the transformer, the video tape
Under which condition does Ohm’s law apply? The current must be constant., The power must be constant., The temperature must be constant., The
Energy is represented by the letter E, current by I, power by P, charge by Q, p.d. by V and time by t.Which pair of equations is correct? E = It and P = VIt, E = VQ / t and P = VI, E = VIt and P = VI, E = VQ and P = VI / t
The case of an electric fan is earthed. The plug to the fan contains a 5 A fuse. There is a current of 4 A when the fan works normally.The cable to the fan becomes so worn that the live wire makes electrical contact with the metal case. What happens? The current flows to earth and the fuse is not affected., The fuse melts and switches off the circu
Which single-coil motor will have the largest turning effect? 6 A 100 no, 10 A 200 no, 6 A 100 yes, 10 A 200 yes
The half-life of a radioisotope is 2400 years. The activity of a sample is 720 counts / s. How long will it take for the activity to fall to 90 counts / s? 300 years , 2400 years , 7200 years, 19 200 years
The neutral atoms of all isotopes of the same element contain the same number of electrons and protons., electrons and neutrons., neutrons only., neutrons and protons