Question
Explain direct current direct emf and draw their graphs. Define alternating current and explain in detail.
✓
Answer
SELF
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
Compute induced current and induced charge in electromagnetic induction and also write Fleming's right hand rule.
Derive an expression for equivalent capacitance of three capacitors when connected
i. in series and
ii. in parallel.
i. in series and
ii. in parallel.
A 60W load is connected to the secondary of a transformer whose primary draws line voltage. If a current of 0.54A flows in the load, what is the current in the primary coil? Comment on the type of transformer being used.
A solid wire of radius 10cm carries a current 5.0A distributed uniformly over its cross-section. Find the magnetic field B at a point at a distance (a) 2cm (b) 10cm and (c) 20cm away from the axis. Sketch a graph of B versus x for 0 < x < 20cm.
Potassium-40 can decay in three modes. It can decay by $\beta^-$-emission, $\beta^+$-emission of electron capture.
→- Write the equations showing the end products.
- Find the Q-values in each of the three cases. Atomic masses of $\text{ }^{40}_{18}\text{Ar},\text{ }^{40}_{19}\text{K}$ and $\text{ }^{40}_{20}\text{Ca}$ are 39.9624u 39.9640u and 39.9626u respectively.
A body of mass m makes an elastic collision with another identical body at rest. Show that if the collision is not head-on, the bodies go at right angle to each other after the collision.
Four identical monochromatic sources A,B,C,D as shown in the (Fig.) produce waves of the same wavelength λ and are coherent. Two receiver $R_1$ and $R_2$ are at great but equal distaces from B.
→
- Which of the two receivers picks up the larger signal?
- Which of the two receivers picks up the larger signal when B is turned off?
- Which of the two receivers picks up the larger signal when D is turned off?
- Which of the two receivers can distinguish which of the sources B or D has been turned off?
Figure shows a potentiometer with a cell of 2.0V and internal resistance of $0.40\Omega$ maintaining a potential drop across the resistor wire AB. A standard cell which maintains a constant emf of 1.02V (for very moderate currents upto a few mA) gives a balance point at 67.3cm length of the wire. To ensure very low currents drawn from the standard cell, a very high resistance of $600\text{k}\Omega$ is put in series with it, which is shorted close to the balance point. The standard cell is then replaced by a cell of unknown emf and the balance point found similarly, turns out to be at 82.3cm length of the wire.
→
- What is the value of $\varepsilon?$
- What purpose does the high resistance of $600\text{k}\Omega$ have?
- Is the balance point affected by this high resistance?
- Is the balance point affected by the internal resistance of the driver cell?
- Would the method work in the above situation if the driver cell of the potentiometer had an emf of 1.0V instead of 2.0V?
- Would the circuit work well for determining extremely small emf, say of the order of few mV (such as the typical emf of a thermo couple)? If not, how would you modify the circuit?
Figure is the plot of the stopping potential versus the frequency of the light used in an experiment on photoelectric effect. Find.
- The ratio h/e and.
- The work function.
Consider an assembly of three conducting concentric spherical shells of radii a, b and c as shown in figure. Find the capecitance of the assembly between the poima A and B
