Question 2 :
If $v$, $P$ and $E$ denote the velocity, momentum and kinetic energy of the particle, then:<br/>
Question 4 :
Six electric appliances of 100 watts each are used for 6 hours. The electrical energy consumed is:
Question 9 :
Assertion: Kilowatt Hour is the unit of electric power
Reason: KWH is a commercial unit used for expressing consumed electrical energy.
Question 12 :
A car of mass $2,000 kg$ is lifted up a distance of $30 m$ by a crane in $1\ minute$. A second crane does the same job in $2\ minutes$.The power supplied by first crane is:
Question 16 :
Which of the following can be used to express energy? Symbols have their usual meanings for the units of physical quantities.<br/>(i) Wh   (ii) VC    (iii) VAs$^2$  (iv)  A$^2\Omega$s<br/>
Question 18 :
An engine lifts a load of $1200\ N$ from a depth of $200 \ m$ in 4  minutes bringing it to the ground level. The power developed by the engine is:
Question 19 :
Which of the following must be known in order to determine the power output of an automobile? <br>
Question 20 :
A car of mass $2,000 kg$ is lifted up a distance of $30 m$ by a crane in $1\ minute$. A second crane does the same job in $2\ minutes$. The power supplied by second crane is:
Question 21 :
Helios-B spacecraft had a speed of $71$ km/s when it was $4.3 \times 10^7 km$ from the sun. Its orbit is
Question 23 :
An electric pump draws water from a well of depth $50 m$ at a rate of $2 m^{3}$ per second. The water is ejected from the pump with velocity, $v = 10 m s^{-1}$. If the efficiency of the pump $\eta  = 80%$, the input power consumption of the pump is: $(g= 10 ms^{-2})$
Question 24 :
Three particles of mass $M$ each are placed at corners of an equilateral triangle of side $'d'$ if the sides are increased to $'2d'$ then :
Question 25 :
The power of sound from the speaker of a radio is 20 milliwatt. By turning the knob of the volume control the power of the sound is increased to 400 milliwatt . The power increase in decibels as compared to the original power is
Question 26 :
Compute the power at which a 250 g squirrel will climb up on a tree at a rate of 0.5 $ms^{-1}$ against the force of gravity? (given $g = 10 \ ms^{-2}$)
Question 27 :
Let $V_G$ and $E_G$ denote gravitational potential and field respectively, the it is possible to have
Question 28 :
A water pump of power $2kW$ is installed in a home. Then, the amount of water (in litres) it can raise in, one minute to a height of $10m$ is :<br/>[Take $g =10 m/ s^2$] 
Question 29 :
A tank on the roof of a $20$ m high building can hold $10\: m^{3}$ of water. The tank is to be filled from a pond on the ground in $20$ minutes. If the pump has an efficiency of $60$%, the input power required is
Question 30 :
Avinash can run with a speed of $8 \:m \:s^{-1}$ against the frictional force of 10 N, and Kapil can move with a speed of $3 \:m \:s^{-1}$ against the frictional force of 25 N. Who is more powerful?<br>
Question 31 :
If the rate of electricity is rupee one per unit, then, a 20 h. p. electric motor, having approx. 100% efficiency will require how much cost (Rs.) on 100 hours running to irrigate the field ?
Question 32 :
A pump is used to lift $500\ kg$ of water from a depth of $80\ m$ in $10\ s$. Calculate the power rating of the pump if its efficiency is $40\%$ :<br/>
Question 33 :
A car of mass 2,000 kg is lifted up a distance of 30 m by a crane in 1 minute. A second crane does the same job in 2 minutes. The power supplied by second crane is :<br/>
Question 34 :
A boy climbs up a hill, which rises 1 m in every  25 secs, on his bicycle. The mass of the boy and his bicycle is 120 kg. What is the power applied by the boy if he is cycling at the rate of 6km/hour? 
Question 35 :
A machine gun fires $180$ bullets $per\ minute$ with a velocity of $300 \ m s^{-1}$. If the mass of each bullet is $10 gm$, the power of the machine gun will be:
Question 37 :
If a satellite is moved from one stable circularorbit to a farther stable circular orbit, then thefollowing quantity increases<br>
Question 38 : On the surface of earth acceleration due to gravity is g and gravitational potential is V.<br/><table class="wysiwyg-table"><tbody><tr><td>Column-I</td><td>Column-II</td></tr><tr><td>a) At height h = R, value of g</td><td>(p) decreases by a factor 1/4</td></tr><tr><td>(b) At depth h = R/2 value of g</td><td>(q) decreases by a factor 1/2</td></tr><tr><td>(c) At height h = R, of V</td><td>(r) Increases by a factor 11/8</td></tr><tr><td>(d) At depth h = R/2 of V </td><td>(s) Increases by a factor 2<br/>(t) None</td></tr></tbody></table><br/>
Question 39 :
How many hours would make a day if earth were rotating at such a high speed that the weight of a body on the equator were zero
Question 40 :
The percentage change in the acceleration of the earth towards the Sun from a total eclipse of the Sun to the point where the Moon is on a side of earth directly opposite to the Sun is<br>
