Download App

Model Paper 3 — Physics STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 SciencePhysicsModel Paper 33 Marks
Question
A heating element using nichrome connected to a 230 V supply draws an initial current of 4.6 A which settles after a few seconds to a steady value of 2.3 A . What is the steady temperature of the heating element if the room temperature is $27^{\circ} C$. [ $\left.\alpha=1.7 \times 10^{-4}{ }^{\circ} C ^{-1}\right]$
✓

Answer

Self

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "3 Marks Question" from Model Paper 3→Model Paper 3 — all question types→Physics STD 12 Science question papers→Gujarat Board STD 12 Science question papers→Gujarat Board question paper generator→

Similar questions

Two parallel plate capacitors X and Y have the same area of plates and same separation between them. X has air between the plates while Y contains a dielectric medium of $\varepsilon_{\text{r}} = 4.$

  1. Calculate capacitance of each capacitor if equivalent capacitance of the combination is $4\mu\text{f}.$
  2. Calculate the potential difference between the plates of X and Y.
  3. Estimate the ratio of electrostatic energy stored in X and Y.
→
Suppose the rod in the previous problem has a mass of 1kg distributed uniformly over its length:
  1. Find the initial angular acceleration of the rod.
  2. Find the tension in the supports to the blocks of mass 2kg and 5kg.
→
Three light rays red (R), green (G) and blue (B) are incident on a right-angled prism ‘abc’ at face ‘ab’. The refractive indices of the material of the prism for red, green and blue wavelengths are 1.39, 1.44 and 1.47 respectively. Out of the three which colour ray will emerge out of face ‘ac’? Justify your answer. Trace the path of these rays after passing through face ‘ab’.

→
  1. The refractive index of glass is 1.5. What is the speed of light in glass? (Speed of light in vacuum is 3.0 × 108 ms–1).
  2. Is the speed of light in glass independent of the colour of light? If not, which of the two colours red and violet travels slower in a glass prism?
→
A disc of radius 10cm is rotating about its axis at an angular speed of 20rad/s. Find the linear speed of:
  1. A point on the rim.
  2. The middle point of a radius.
→
An electric bulb, when connected across a power supply of 220V, consumes a power of 60W. If the supply drops to 180V, what will be the power consumed? If the supply is suddenly increased to 240V, what will be the power consumed?
→
Describe the working principle of a moving coil galvanometer. Why is it necessary to use (i) a radial magnetic field and (ii) a cylindrical soft iron core in a galvanometer? Write the expression for current sensitivity of the galvanometer.
Can a galvanometer as such be used for measuring the current? Explain.
→
Describe principle and construction of AC generator with figure and discuss its working.
→
For a system made of two very long coaxial solenoids, explain mutual inductance. Prove $M _{12}= M _{21}= M$ (Reciprocity Theorem).
→
Calculate the Q-value of the fusion reaction
4He + 4He = 8Be.
Is such a fusion energetically favourable? Atomic mass of 8Be is 8.0053u and that of 4He is 4.0026u.
→