Old Exam Questions Chapter 27 (Dr. GondalPhys102)
T071
Q13. A single loop circuit contains two external resistors and two emf sources as shown in the figure 1. Assume the
emf sources are ideal, what is the power dissipation across resistor R1. (Ans: 0.9 W)
Q14. A capacitor of capacitance 5.0x106 F is discharging through a 4.0 M Ω resistor. At what time will the energy
stored in the capacitor be half of its initial value? (Ans: 7 s)
Q15. Four resistors are connected as shown in the figure 2. What is the current through R1, when a potential
difference of 30.0 Volts is applied between points a and b? (Ans: 1.75 A)
Q16. If Va – Vb = 3.2 V, what is Vd – Vc shown in Figure 3 ? (Ans:
9.6 V)
Q17. The figure below shows 3 identical light bulbs connected to a battery. What happens to the power of light bulb
1 when the switch S is closed in Figure 4? (Ans: The power increases)
Fig#
Fig. 3, T071
Fig.2, T071
Fig. 1, T071
Fig. 4, T071
T062
Q13. A 6V battery supplies a total of 48 W to three identical light bulbs connected in parallel. The resistance of each bulb is:
(Ans: 2.25
Ω
)
Q14.In the following figure 1, find the current in 3
Ω
resistor and the resistance R for the given currents. (Ans: 8 A,
9
Ω
)
Q15. Two resistors
r
and
R
are connected in series across 100 V line. If
r
= 30 k
Ω
and the voltage across it is found to be 60
V, find the resistance of
R
. (Ans: 20
k
Ω
)
Q16. A 30.0 k
Ω
resistor and a capacitor are connected in series and a 15.0 V potential difference is suddenly applied across
them. The potential difference across the capacitor rises to 5.00 V in 1.50 µs. Find the capacitance of capacitor(Ans: 123 pF)
Q17. Four resistors , each of 20Ω, are connected in parallel and the combination is connected to a 20 V
emf device. The
current in any one of the resistors is: (Ans: 1.0 A)
1
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View Full DocumentT052:
Q#6
. In the figure 1 shown, each resistance is 1
Ω
. Calculate the emf of the battery if the current I is 4 A.
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 Spring '10
 SHIH
 Power, Volt, Resistor, 4ohm, 0.9 W

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