Arrange the following electromagnetic radiation in the order of decreasing energy.
A. Infrared waves B. Ultraviolet rays
C. Orange light D. Green light
B, C, A, D
D, A, C, B
B, D, C, A
A, C, D, B
In the circuit, shown in figure, K is open. The charge on capacitor C in steady state is q. Now, key is closed and at steady state, the charge on C is q2 the ratio of charges is
1
When an AC source of emf e = E0 sin (100t) is connected across a circuit, the phase difference between the emf e and the current i in the circuit is observed to be /4, as shown in the diagram. If the circuit consists possibly only of R-C or R-L or L-C is series, find the relationship between the two elements.
R = 1 kΩ , C = 10 µF
R = 1 kΩ , C = 1 µF
R = 1 kΩ , L = 10 H
R = 1 kΩ , L = 1 H
For the circuit shown in figure, the voltage across 4 Ω resistance is
1 V
2 V
4 V
5 V
B.
2 V
Let the currents in the various arms be shown in above figure.
Now using Kirchhoffs voltage law,
For closed loop ABGHA
3 I + 6 (I − I1) − 9 = 0
or 9 I − 6 I1 = 9
or 3 I − 2 I1 = 3 ... (i)
For closed loop BGFGB
4 I1 + 2 (I1 − I2) + 1 × I1 − 6(I − I1) = 0
− 6 I + 13 I1 − 2 I2 = 0 ... (ii)
For closed loop GDEFC
2 I2 + 4 − 2 (I1 − I2) = 0
2 I2 − 4 I2 = 4
I1 − 2 I2 = 2 ... (iii)
From Eq. (i) I = (3 + 2 I1)/3
From Eq. (ii) I2 = (I1 − 2)/2
Putting these values in Eq. (ii), we get
On solving I1 = 0.5 A
Potential difference across 4 Ω = 0.5 × 4 = 2 V
Three solenoid coils of same dimensions, same number of turns and same number of layers of windings are taken. Coil 1 with inductance L1 was wound using a wire of resistance 11 Ω /m, coil 2 with inductance L2 was wound using the similar wire but the direction of winding was reversed in each layer, coil 3 with inductance L3 was wound using a superconducting wire. The self inductance of the coils L1 , L2 and L3 are
L1 = L2 = L3
L1 = L2 , L3 = 0
L1 = L3 , L2 = 0
L1 > L2 > L3
A long hollow conducting cylinder is kept co-axially inside another long and hollow conducting cylinder of larger radius. Both the cylinders are initially electrically neutral.Now consider the following statements
Which of the above mentioned statement is/are correct?
Only I
I, IV
Only II
Only III
An iron rod of volume 10-4 m3 and relative permeability 1000 is placed inside a long solenoid having 5 turns/cm. If a current of 5.0 A is passed through the solenoid, then magnetic moment of the rod is
20 A-m2
25 A-m2
30 A-m2
35 A-m2
Two electric bulbs rated 50W and 100W are glowing at full power, when used in parallel with a battery of emf 120 V and internal resistance 10 Ω. The maximum number of bulbs that can be connected in the circuit when glowing at full power is
6
4
2
8
A LED has a voltage drop of 2V across it and passes a current of 10 mA. When it operates with a 6V battery through a limiting resistor R. The value of R is
40 kΩ
200 Ω
4 kΩ
400 Ω
In a region, the potential is represented by V (x,y,z) = 6x − 8xy − 8y + 6yz where V is in volts and x,y,z are in meters. The electric force experienced by a charge of 2C situated at point (1,1,1) is
30 N
24 N