MCQ
Fire is extinguished more effectively by
- ✓Hot water
- BCold water
- CEqually by both
- DIce
✓
Answer
Correct option: A.
Hot water
a
(a) Fire is extinguished by the vaporisation do water which lowers the temperature of the burning body. Further, the water vapour envelops the body, keeping oxygen away. Hot water evaporates more than cold water as
(a) Fire is extinguished by the vaporisation do water which lowers the temperature of the burning body. Further, the water vapour envelops the body, keeping oxygen away. Hot water evaporates more than cold water as
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
Which of the following dimensions will be the same as that of time?
The maximum velocity (in $ms^{-1}$) with which a car driver must traverse a flat curve of radius $150 \,m$ and coefficient of friction $0.6$ to avoid skidding is
→A body is moving with a velocity $v$, breaks up into two equal parts. One of the part retraces back with velocity $v$. Then the velocity of the other part is
→A uniform solid cylinder of mass $M$ and radius $R$ can freely rotate around its axis $O$ . There is a elastic string of relaxed length $L$ and stiffness $K$ attached to the cylinder and a static wall. Initially, the string is relaxed. As the cylinder starts rotating, the string will wind the cylinder. The surface of cylinder is very rough, so that the string does not slip on the cylinder’s surface. The minimum initial angular speed of the cylinder, ${\omega _0}$ , so that it can rotate to angle $2\pi $ is (Assume Hooke’s law to be valid.)
→‘Gulab Jamuns’ (assumed to be spherical) are to be heated in an oven. They are available in two sizes, one twice bigger (in radius) than the other. Pizzas (assumed to be discs) are also to be heated in oven. They are also in two sizes, one twice big (in radius) than the other. All four are put together to be heated to oven temperature. Choose the correct option from the following:
The acceleration of a train travelling with speed of $400 \,m/s$ as it goes round a curve of radius $160\,m$, is
→The coefficient of volume expansion of glycerin is $49 \times 10^{-5} \,K ^{-1}$. The fractional change in the density on a $30^{\circ} C$ rise in temperature is ..........
→The property of a body by virtue of which it tends to regain its original size and shape of a body when applied force is removed, is known as:
The periodic function $\text{f(t)}=\text{A}\sin(\omega\text{t})$ repeats itself with periodic function of:
→A ball is dropped from a height and falls due to gravity and wind simultaneously imparts it a uniform horizontal acceleration. Which one of the following figures best represents its path?