#1. Which one of the following forms of energy is conserved in biogas?
#2. Figure 4 shows a rectangular framework which can be sheared by force. The framework will resist the shear due to the force if the beam is fixed along
#3. The energy change that takes place when a hot metal releases an electron is
Heat energy >> Potential energy
Potential energy >> Kinetic energy
Heat energy >> Kinetic energy
Heat energy >> Electrical energy
#4. An atom becomes positively charged when it loses an electron because
an atom has equal number of protons and electrons
the nucleus contains neutrons and protons
electrons are negatively charged
there will be more positive charge than negative charge
#5. The time that elapses between the lightning flash and thunder is 5 s. Find the distance of the cloud from the observer, (sveed of’sound in air is 330 ms-1)
#6. Which one of the following statements is true about the self-induced e.m.f of a coil?
It acts to increase the e.m,f if the current through the coil is increasing
It acts to decrease the e.m.f if the current through the coil is increasing
It is always in the same direction as the current
it depends on the rate of change of current
#7. When no external forces act on two bodies in a collision, the total momentum of the bodies
is proportional to product of their masses
#8. Which one of the following optical devices can be used as a solar concentrator?
#9. Thermionic emission occurs (I) in all metals. (ii) when electrons gain enough thermal energy. (iii) when accelerating voltage is applied at the anode.
(ii) and (iii) only
(j) and (iii) only
#10. A kettle rated 1200 W contains 2 kg of water at 25°C. How long would it take to raise the temperature of the water to 85°C if 80% of the electrical energy supplied is absorbed by the water?
#11. A negatively charged pointed conductor mounted on an insulated stand loses charge in air because
negatively charged ions are attracted to it
negatively charged ions are repelled by it
positively charged ions are repelled by k
positively charged ions are attracted to it
#12. An object of height 1cm is placed 4 cm from a convex lens forms an image five times the height of the object. Find the distance of the image from the lens.
#13. Which of the following is correct about current that flows through resistors connected in series?
Current increases as it flows through the resistors
Current decreases as it flows through the resistors
Current through each of the resistors is proportional to the resistance
Current through each of the resistors is the same
#14. A heating element of resistance 40 C2 produces 360 kJ of heat in 5mins. Find the current flowing through the element.