In a Wheatstone bridge, three resistors P,Q, R are connected in three arms in order and 4th arm of resistance, s, is formed by two resistors s1 and s2 connected in parallel. The condition for bridge to be balanced is, P/Q
Two cells of E.M.F. 10 V and 2 V and internal resistances 10 Ω and 5 Ω respectively, are connected in parallel as shown. Find the effective voltage across R.
A network of resistors is connected to a 16 V battery with internal resistance of 1 Ω, as shown in the following figure. Compute the equivalent resistance of the network.
A 10 V battery of negligible internal resistance is connected across a 200 V battery and a resistance of 38Ω as shown in the figure. Find the value of the current in the circuit.
In the circuit shown in the figure, find the total resistance of the circuit and the current in the arm CD.
What is relaxation time ? Derive an expression for resistivity of a wire in terms of number density of free electrons and relaxation time.
A 100 V battery is connected to the electric network as shown. If the power consumed in the 2 Ω resistor is 200 W, determine the power dissipated in the 5 Ω resistor.
Five resistances are combined according to the figure. The equivalent resistances between the points X and Y will be
(a) 10 Ω
(b) 22 Ω
(c) 20 Ω
(d) 50 Ω
Wave theory of light cannot explain the phenomena of
1. Polarisation 2. Diffraction 3. Interference 4. Crompton effect 5. Photoelectric effect
(A) 3, 4
(C) 1 ,2
(B) 1, 4, 5
(D) 4 ,5
To obtain a sustained interference pattern we require two sources which emit radiation of
(A) the same frequency
(B) nearly same frequency
(C) the same frequency having a definite phase relationship
(D) different wavelengths
Electric flux emanating through a surface element placed in an electric field is
(A) 10 units
(B) 20 units
(C) 4 units
(D) 16 units
When interference of light takes place
(a) energy is created in the region of maximum intensity
(b) energy is destroyed in the region of maximum intensity
(c) conservation of energy holds good and energy is redistributed
(d) conservation of energy does not hold good
In a double slit interference pattern, the first maxima for infrared light would be
(a) at the same place as the first maxima for green light
(b) closer to the centre than the first maxima for green light
(c) farther from the centre than the first maxima for green light
(d) infrared light does not produce an interference pattern
Two sources of light are said to be coherent, when they give light waves of same
(a) amplitude and phase.
(b) wavelength and constant phase difference.
(c) intensity and wavelength.
(d) phase and speed.