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#### Term 1 Five Mark Model Questions

12th Standard EM

Reg.No. :
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Physics

Time : 01:00:00 Hrs
Total Marks : 25
5 x 5 = 25
1. When two objects are rubbed with each other, approximately a charge of 50 nC can be produced in each object. Calculate the number of electrons that must be transferred to produce this charge.

2. Two electric bulbs marked 20 W – 220 V and 100 W – 220 V are connected in series to 440 V supply. Which bulb will be fused?

3. What is the value of x when the Wheatstone’s network is balanced?
P = 500 Ω, Q = 800 Ω, R = x + 400, S = 1000 Ω

4. A cell supplies a current of 0.9 A through a 2 Ω resistor and a current of 0.3 A through a 7 Ω resistor. Calculate the internal resistance of the cell.

5. In a plane Electromagnetic wave the electric field oscillates sinusoidally at a frequency of 1.5 X 1010Hz & amplitude 36 Vm-1.
(i) What is the wavelength of a wave?
(ii) What the amplitude of the oscillating magnetic field?
(iii) Straight the average energy density of the electric field $\left( \overrightarrow { E } \right)$ , is equal to average energy density of the magnetic field $\left( \overrightarrow { B } \right)$