1
AIPMT 2012 Prelims
MCQ (Single Correct Answer)
+4
-1
Change Language
If voltage across a bulb rated 220 volt-100 watt drops by 2.5% of its rated value, the percentage of the rated value by which the power would decrease is
A
20%
B
2.5%
C
5%
D
10%
2
AIPMT 2012 Prelims
MCQ (Single Correct Answer)
+4
-1
Change Language
In an electrical circuit R, L, C and a.c. voltage source are all connected in series. When L is removed from the circuit, the phase difference between the voltage and the current in the circuit is If instead, C is removed from the circuit, the phase difference is again. The power factor of the circuit is
A
$${1 \over 2}$$
B
$${1 \over {\sqrt 2 }}$$
C
1
D
$${{\sqrt 3 } \over 2}$$
3
AIPMT 2012 Prelims
MCQ (Single Correct Answer)
+4
-1
Change Language
The current $$(I)$$ in the inductance is varying with time according to the plot shown in figure.

AIPMT 2012 Prelims Physics - Alternating Current Question 53 English
Which one of the following is the correct variation of voltage with time in the coil ?
A
AIPMT 2012 Prelims Physics - Alternating Current Question 53 English Option 1
B
AIPMT 2012 Prelims Physics - Alternating Current Question 53 English Option 2
C
AIPMT 2012 Prelims Physics - Alternating Current Question 53 English Option 3
D
AIPMT 2012 Prelims Physics - Alternating Current Question 53 English Option 4
4
AIPMT 2012 Prelims
MCQ (Single Correct Answer)
+4
-1
Change Language
A coil of resistance 400 $$\Omega $$ is placed in a magnetic field. If the magnetic flux $$\phi $$ (Wb) linked with the coil varies with time t (sec) as $$\phi = 50{t^2} + 4$$.

The current in the coil at t = 2 sec is
A
0.5 A
B
0.1 A
C
2 A
D
1 A