If we change the value of \(R,\) then:
  

1. voltage does not change on \(L\)

2. voltage does not change on \(LC\) combination

3. voltage does not change on \(C\)

4. voltage changes on \(LC\) combination

If \(V=ar\) where \(a\) is a constant and \(r\) is the distance, then the electric field at a point will be proportional to:
1. \(r\)
2. \(r^{-1}\)
3. \(r^{-2}\)
4. \(r^{0}\)

Electric field at point 20 cm away from the centre of a dielectric sphere is 100 V/m, the radius of the sphere is 10 cm, then the value of the electric field at a distance 3 cm from the centre is:

1. 100 V/m

2. 125 V/m

3. 120 V/m

4. 0

50 g ice at 0°C in insulator vessel, 50 g water of 100 °C is mixed in it, and then final temperature of the mixture is: (neglect the heat loss)
1. 10°C
2. 0°C << T_m < 20°C
3. 20°C
4. above 20°C

Real power consumption in a circuit is least when it contains:
1. High \(R\), low \(L\) 
2. High \(R\), high \(L\) 
3. Low \(R\), high \(L\) 
4. High \(R\), low \(C\)

The linear density of a string is \(1.3\times 10^{-4}~\mathrm{kg/m}\) and the wave equation is \(y=0.021\sin(x+30t)\). 
What is the tension in the string, where \(x\) is in meters and \(t\) in seconds?
1. \( 0.12 \mathrm{~N} \)
2. \( 0.21 \mathrm{~N} \)
3. \(1.2 \mathrm{~N} \)
4. \( 0.012 \mathrm{~N}\)

Magnetic field at point O will be: (assume straight wire segments are infinite)
    
1. \(\frac{\mu_{_0}l}{2R}\) interior
2. \(\frac{\mu_{_0}l}{2R}\) exterior
3. \(\frac{\mu_{_0}l}{2R}1-\frac{l}{\pi}\) interior
4. \(\frac{\mu_{_0}l}{2R}1-\frac{l}{\pi}\) exterior

In Young's double-slit experiment, the spacing between two slits is \(0.1\) mm. If the screen is kept at \(1.0\) m from the slits and the wavelength of light is \(5000\) Å, then the fringe width is:
1. \(5\) cm
2. \(0.5\) m
3. \(1\) cm
4. \(0.5\) cm

According to Bohr's model of a hydrogen atom, the relation between the principal quantum number \(n\) and the radius of the stable orbit is:
1. \(r\propto\frac1n\)
2. \(r\propto n\)
3. \(r\propto\frac{1}{n^2}\)
4. \(r\propto n^2\)

An observer is approaching with velocity \(v\) towards a light source. If the velocity of light is \(c,\) then the velocity of light with respect to the observer will be:
1. \(c-v\)
2. \(c\)
3. \(c+v\)
4. \(\sqrt{1-v^2/c^2}\)