Two amplifiers of voltage gain 20 each, are cascaded in series. If 0.01 volt a.c. input signal is applied across the first amplifier, the output a.c. signal of the second amplifier in volts is:
1. 2.0
2. 4.0
3. 0.01
4. 0.20
A hollow metal sphere of radius \(R\) is given \(+Q\) charges to its outer surface. The electric potential at a distance \(\dfrac{R}{3}\) from the centre of the sphere will be:
1. \(\dfrac{1}{4\pi \varepsilon_0}\dfrac{Q}{9R}\)
2. \(\dfrac{3}{4\pi \varepsilon_0}\dfrac{Q}{R}\)
3. \(\dfrac{1}{4\pi \varepsilon_0}\dfrac{Q}{3R}\)
4. \(\dfrac{1}{4\pi \varepsilon_0}\dfrac{Q}{R}\)
The dimensions of mutual inductance \((M)\) are:
1. \(\left[M^2LT^{-2}A^{-2}\right]\)
2. \(\left[MLT^{-2}A^{2}\right]\)
3. \(\left[M^{2}L^{2}T^{-2}A^{2}\right]\)
4. \(\left[ML^{2}T^{-2}A^{-2}\right]\)
The plot of current \(I~\text{(A)}\) flowing through a metallic conductor versus the applied voltage \(V~\text{(volt)}\) across the ends of a conductor is:
1. | 2. | ||
3. | 4. |
A network of resistors is connected across a \(10~\text{V}\) battery with an internal resistance of \(1~\Omega\) as shown in the circuit diagram. The equivalent resistance of the circuit is:
1. | \(\dfrac{17}{3}~\Omega\) | 2. | \(\dfrac{14}{3}~\Omega\) |
3. | \(\dfrac{12}{7}~\Omega\) | 4. | \(\dfrac{14}{7}~\Omega\) |
When a body of mass \(m\) just begins to slide as shown, match List-I with List-II:
List-I | List-II | ||
(a) | Normal reaction | (i) | \(P\) |
(b) | Frictional force \((f_s)\) | (ii) | \(Q\) |
(c) | Weight \((mg)\) | (iii) | \(R\) |
(d) | \(mg \mathrm{sin}\theta ~\) | (iv) | \(S\) |
(a) | (b) | (c) | (d) | |
1. | (ii) | (i) | (iii) | (iv) |
2. | (iv) | (ii) | (iii) | (i) |
3. | (iv) | (iii) | (ii) | (i) |
4. | (ii) | (iii) | (iv) | (i) |
1. | \(10~\text{J}\) | 2. | \(2.5~\text{J}\) |
3. | \(20~\text{J}\) | 4. | \(5~\text{J}\) |
The value of resistance for the colour code of the given resistor is:
1. \((36\pm36)~k\Omega~\)
2. \((470\pm47)~k\Omega~\)
3. \((360\pm36)~k\Omega~\)
4. \((360\pm18)~k\Omega~\)
A concave lens of focal length \(-25\) cm is sandwiched between two convex lenses, each of focal length, \(40\) cm. The power in dioptre of the combined lens would be:
1. | \(55\) | 2. | \(9\) |
3. | \(1\) | 4. | \(0.01\) |
A beam of light is incident vertically on a glass slab of thickness \(1\) cm, and refractive index \(1.5.\) A fraction \(A\) is reflected from the front surface while another fraction \(B\) enters the slab and emerges after reflection from the back surface. The time delay between them is:
1. | \(10^{-10}\) s | 2. | \(5\times 10^{-10}\) s |
3. | \(10^{-11}\) s | 4. | \(5\times 10^{-11}\) s |