Question Text
Question 2 :
Which instrument is not used to convert electric energy into heat energy?
Question 3 :
Match the following:<br/><table class="wysiwyg-table"><tbody><tr><td><b>Section - A</b></td><td><b>Section - B</b></td></tr><tr><td>(1) Fuse</td><td>(P) Converts electric energy into mechanical energy</td></tr><tr><td>(2) Electric Generator</td><td>(Q) Heating effect of electric current</td></tr><tr><td>(3) Electric Motor</td><td>(R) Converts mechanical energy into electrical energy</td></tr></tbody></table>
Question 4 :
If the coil in a simple generator is wound around a soft iron core then:
Question 6 :
An electric fuse used in households works on which principle of:<br/>
Question 7 :
The resistance of wire is 5 ohm at 50C and 6 ohm at 100C. The resistance of the wire at 0C willbe
Question 8 :
The work done by electric field in carrying a point charge of 5$\mu $C from a point A to point B is 10 mJ. The potential difference ${V_A} - {V_B}$ is the:
Question 9 :
In passing through a boundary, refraction will not take place if
Question 10 :
A wave has velocity v in medium P and velocity 2v in medium Q. If the wave is incident in medium P at an angle of 30, then the angle of refraction will be
Question 11 :
A $2 cm$ tall object is placed perpendicular to the principal axis of a convex lens of focal length $1 cm$. If the object distance is $1.5 cm$. Find the magnification.
Question 12 :
A plano-concave lens is made of glass of refractive index $1.5$ and the radius of curvature of its curved face is $100 cm$. What is the power of the lens?<br/>
Question 13 :
What is the role of a plane mirror in a solar cooker?