Question 1 :
Which of the following observations cannot be explained by Tyndall Effect?
Question 5 :
The rising and setting of sun appear red because of : 
Question 6 :
Assertion: Fine particles in atmosphere scatter the light of shorter wavelength more.
Reason: Sky appears blue.
Question 9 :
The resistance of the series combination of two resistances is S. When they are joined in parallel the total resistance is P. If S = nP, then the minimumpossible value of n is
Question 10 :
What is the total resistance when four resistors of $$20, 40, 60$$, and $$80$$ respectively are connected in parallel (in ohm)?
Question 12 :
Two cylindrical rod have area of cross-section$$A_1$$ $$A_2$$. If $$A_1$$ is greater than $$A_2$$. Then which of the following is correct?
Question 13 :
<span class="wysiwyg-font-size-small"><span class="wysiwyg-font-size-small"><p>The work done (in Joule) in carrying a charge of 100 coulomb between two points having a potential difference of 10 volt is:</p>
Question 15 :
A bullet of mass 2 g is having a charge of 2 $$\mu$$ C. Through what potential difference must it be accelerated, starting from rest, to acquire a speed of 10 m/s ?  
Question 16 :
When a metallic conductor is heated then the atoms in the metal vibrate with ?<br/>
Question 17 :
Mark the correctreason/s why nichrome is used for making heating element of electricalappliances.
Question 18 :
How much units of energy is consumed in operating ten 50 watt bulbs for 10 hours per day in a month (30 days)
Question 19 :
Two wires of the same material have lengths 3 cm and 5 cm and radii 1 mm and 3 mm respectively. They are connected in series across a battery of 16 V. The p.d. across the shorter wire is
Question 20 :
The temperature coefficient resistivity of a material is $$0.0004/K$$. When the temperature of the material is increased by $$50^{o}C$$, its resistivity increases by $$2\times 10^{-8}\ ohm-meter$$.The initial resistivity of the material of the resistance
Question 21 :
A point-charge of $$6.0\times 10^{-8}$$ C is situated at the coordinate origin. How much work will be done in taking an electron from the point $$x=3$$m to $$x=6$$m?
Question 22 :
A man sees a smallstationary fish deep in a very clear lake and shoots it accurately. He will
Question 23 :
State whether true or false.<br/>The images formed by a convex mirror are always erect and enlarged.
Question 27 :
State whether true or false : A concave lens will always give a virtual, erect and diminished image.
Question 28 :
The image formed by the given convex mirror when it is inside focal distance is:
Question 29 :
State whether true or false.<br/>A convex mirror always forms a real image.
Question 30 :
A ray of light incident at a point on the principal axis of a convex lens passes undeviated through the lens. What special name is given to this point on the principal axis?<br>
Question 32 :
A light ray travels from optically denser medium to optically rarer medium, if the angle of incidence and refraction at point of incidence are $$\angle i$$ and $$\angle r$$ respectively, then find the angle of deviation in terms of $$\angle i$$ and $$\angle r$$.
Question 33 :
The image of an object formed by a convex lens when the object is placed between the lens and the focal point is -
Question 34 :
A $$2.5$$ dioptre lens forms a virtual image which is $$4$$ times the object placed perpendicularly on the lens. Then the required distance of the object from the lens is .